The June Weather Outlook
Normal temperatures rise at the rate of one degree every four days this month. Average highs move from the upper 70s on the first of June to the middle 80s by the beginning of July. Lows climb from the mid 50s into the lower 60s. The average temperature for the entire month is usually 71.5 degrees, up ten degrees from May. The coldest June recorded here was 65.8 degrees in 1928. The warmest was 78.4 degrees in 1934.

A typical June temperature distribution looks like the  following in much of the state: four days in the 90s, twelve days in the 80s, twelve days in the 70s, two days in the 60s, with a slight chance for one of those cooler days to be in the upper 50s.

The warmest June days, those which carry an 85 percent chance for afternoon highs above 80 degrees: June 13th, 14th, 15th, 21st, 26th. The 13th, 14th, and 15th are the June days most likely to produce highs in the 90s.

The coldest days in the month, those with a 50 percent chance for a high below 80: June 2nd, 3rd, 4th, 5th, 10th, 30th. The driest June days, those with 20 percent chance of rain or less,  are: June 4th, 6th, 10th, 13th, 14th, 16th, 17th, 18th, 21st, 25th, 26th. The period between the 13th and the 26th is historically the best for field work. The 25th and the 26th are almost always free from rain.

The sunniest June days, those which have a 90 percent chance for 12 out of 24 hours without clouds (a thunderstorm is possible, but all-day overcast conditions are rare): June 9th, 10th, 14th, 19th, 21st, 24th, 25th, 26th.

The wettest days this month, those with more than a 40 percent chance for rain: June 2nd, 3rd, 5th, 8th, 11th, 12th, 15th, 20th. The 15th and 20th are usually the rainiest days in June weather history. The first and the last weeks of the month generally provide the most precipitation. About eight thunderstorms occur in a Yellow Springs June.

Summercount
Between the last week of May through the first week  of September, the 14 major cool fronts of summer cross the United States. As these high-pressure systems approach, atmospheric conditions become unsettled, and rain becomes more likely. After the passage of the fronts, weather is ordinarily suitable for outdoor work and recreation. Fronts will reach the Mississippi around the following dates; they will come through about two days earlier in the West, a day or two later in the East.

June 2:  The June 2nd front can bring a light freeze along the Canadian border and at higher elevations, but the rest of the country is typically safe by this time in the year (except for a very slight danger of frost on the morning of the 5th).  After this front weakens, chances for highs in the cool 60s along the 40th Parallel fall to only 15 percent, and 50s are rare. 

June 6:  The low-pressure system that accompanies the June 6th front initiates a four-day period during which there is an increased chance for tornadoes and flash floods.  Even after this front passes to the east, storms often strike up to 40 percent of the years.  Part of the reason for the rise in the risk for severe weather is the increase in the percentage of afternoons in the 80s and 90s almost everywhere in the continental United States.  With the heat, however, comes more sunshine than during any other week so far in the year.   

June 10:  Good chances for a shower precede this weather system, and after its passage, chances are the best so far in the year for a major heat wave.  In all but the northernmost states (and at the highest elevations), lows near freezing and highs only in the 50s or 60s now recede from the realm of serious possibility until late August.  Although showers can be associated with warm temperatures, many of the days between this front and the next are dry.  The sunniest June days usually occur between now and the 26th.  Approximately 100 frost-free days now remain on most farms and gardens of the country.

June 15:  Unsettled conditions often surround the arrival of this front (between the 13th and 16th) as late spring and early summer hold their final skirmishes along the nation’s midsection.  After summer is victorious, precipitation typically stays away for several days.  Between the 15th and the 19th, average temperatures climb their final degrees, reaching their summer peak near solstice.  The period between the 13th and the 26th is historically one of the best times of the month for fieldwork. 

June 23:  The June 23rd high-pressure system is typically cool and dry, and it is often followed by some of the sunniest and driest days of all the year.  Cooler conditions in the 70s or even the 60s are most likely to occur on the 23rd and 24th, as the front arrives, but then the afternoons usually warm to the 80s or 90s.  As the next June front approaches, the benign effects of the June 23rd system can be expected to give way to storms.

June 29:  The final weather system of the month is almost always followed by the Corn Tassel Rains, a two-week period of intermittent precipitation that accompanies the Dog Days of middle summer.  If your land has been dry throughout June, the Corn Tassel Rains bring the first real chance of midsummer moisture.  In spite of the association of the Corn Tassel Rains with heat, the final two days of June are sometimes the coldest of the year’s midsection, highs below 80 degrees occurring more than half the time above the Border States.

WEEKLY WEATHER FOR JUNE

WEEK 1
The first week of June brings a sudden end to the likelihood of highs in the 50s and 60s at average elevations along the 40th parallel. Chances for that kind of cold were around 30 percent last week; this week, chances for 60s fall to only 15 percent, and 50s are rare.
Temperatures rise into the 70s on 35 percent of the afternoons, into the 80s on 40 percent, and into the 90s on ten percent. After June 6th, the likelihood of highs reaching into the 90s jumps to 20 percent. Only about 15 percent of the nights bring lows in the 30s or 40s.
Rainfall is usually lighter this week than last, and the sun shines more. Still, showers fall about 40 percent of the time each day, except for the 4th, which has just a 30 percent chance, and the 6th, historically one of the driest days of June, which has just a 15 percent chance for precipitation.

WEEK 2
The second week of June always brings an increase in the likelihood of highs in the 90s, and the average percentage of afternoons in the 80s rises above the average percentage for 70s for the first time in the year. Highs in the cold 60s are rare, occurring just five percent of the time.
This week also brings more sunshine than almost any other week so far in the year: 85 percent of the days have at least partly cloudy skies. And the week also contains one of the driest days of the month, June 10th, which brings a shower only 15 percent of the years. The 13th and 14th are also usually dry, both having just a 20 percent chance for rain. The wettest days in the period are June 8th, 9th, 11th and 12th, each having a 40 percent chance for rain.
Between June 8th and 11th, the average temperature rise slows to one degree in four days instead of late spring’s one degree in three. Then, between the 15th to the 19th, it climbs just one degree in five days, reaching its summer zenith.

WEEK 3
The likelihood of rain diminishes this week of the year, and the period brings four days that are usually favorable for field work. Chances for completely overcast conditions decline to less than 20 percent. The 16th, 17th, and 18th have a very low incidence of rainfall (just 20 percent chance for showers), and chances on the 21st are only 30 percent. The 20th, however, has a 50 percent chance for thunderstorms.
Temperatures are usually warm, with only 35 percent of the afternoon highs remaining below 80 degrees. Hot 90s occur at least 20 percent of the time. Lows are in the 60s the majority of nights, but 50s and 40s occur up to 40 percent of the time.

WEEK 4
Sunny skies are the rule for the last quarter of June: clouds dominate less than 20 percent of all the days, and that makes this period one of the brighter ones in the whole year. Daily chances for rain throughout this period of the month are 30 percent except on the 25th and 26th; those two days are some of the driest of the entire year, carrying only a ten percent chance for precipitation. High temperatures rise into the 80s at least 60 percent of all the afternoons and climb above 90 on 20 percent of the days. Cooler conditions in the 70s or even the 60s are most likely to occur on the 23rd and 24th.

FROSTWATCH
A very slight chance (1 to 3 percent) of frost remains until the 14th of June in the lower Midwest. In the most capricious years in the northern tier of states, however, frost can strike at almost any time.

SUMMERCOUNT
Between the last week of May through the first week of September, 14 major cool fronts cross the United States. As these high-pressure systems approach, atmospheric conditions become unsettled, and rain becomes more likely. After the passage of the fronts, look for weather suitable for outdoor work and recreation. Fronts will reach the Midwest around the following dates; they will come through about two days earlier in the West, a day or two later in the East.

June 2: This is the last dangerous front for frost in the northern states, but a freeze is rare in other parts of the United States.

June 10: A heat wave often follows this front.

June 16: This front typically brings precipitation. If it is dry, however, it reinforces a dry June.

June 23: This high-pressure system ordinarily sweeps the Midwest, and then the East, clean of clouds. Look for three to four days of warm clear weather.

June 29: Showers typically occur at the arrival of this front; they often linger through Independence Day, becoming the traditional “Corn Tassel Rains.”

THE DAILY WEATHER HISTORY
June 1
Today brings a ten percent chance for highs in the 90s, fifty percent for 80s, thirty percent for 70s, and ten percent for 60s. A thunderstorm comes 40 percent of the time, and the sun shines eight years in a decade. A very slight chance (one to three percent) of frost remains across the North until the 14th of June.
June 2
Most June 2nds are pleasant and warm with highs in the 70s or 80s (35 percent chance for each), with the remaining 30 percent evenly divided between 90s and 60s. Completely cloudy conditions occur four days out of ten. Rain falls 55 percent of the time on this date, but this is the last day until June 20th that chances of precipitation are so high.
June 3
Today’s high temperature distribution: 80s occur on 45 percent of all the days, 70s on 35 percent, and 60s on 20 percent. Highs rarely reach 90 on June 3rd. Thunderstorms develop 45 percent of the years, but the sun returns 90 percent of the time
June 4
The 4th is usually dry, with showers occurring just 25 percent of the days. Skies are clear to partly cloudy three days in four. Highs reach the 80s forty percent of the time and climb to the 70s fifty-five percent of the time. Today is the second-last June day on which a five percent chance for cold afternoon temperatures in the 50s can be expected (the 12th is the very last day).
June 5
Today's chance for a high in the 90s is five percent, and 90s are at least that likely at average elevations along the 40th Parallel until September 19th. Fifty percent of the afternoons reach 80, and 30 percent are in the 70s. Chilly afternoons in the 60s come 15 percent of the time. A low in the 30s is more likely (ten percent likely) to occur this morning than on any other June morning, and it is the last time that temperatures so cold can be expected until September 6th.
June 6
This is one of the four driest days in June, and rain passes through only once in a decade. Skies are clear 80 percent of the years, and the likelihood of temperatures in the 90s rises to 25 percent for
the first time this summer. Eighties occur 30 percent of the years, 70s forty percent, and there is only a slight possibility for cool 60s.
June 7
Skies are overcast more often on the 7th than on any other day of the month (55 percent of the time). Rain, however, comes an average of just one year in three. Temperatures are almost always above 70. There is a 15 percent chance for heat in the 90s, fifty percent for a high in the 80s, thirty-five percent for 70s.
June 8
This is one of the sunnier June days; it has a 90 percent chance for clear to partly cloudy conditions. Thunderstorms, however, occur about half the time. Temperatures are above 90 twenty-five percent of the years, in the 80s fifty-five percent, in the 70s fifteen percent. Low temperatures remain above 60 degrees 40 percent of the nights. A cool dawn in the 40s happens between five and 15 percent of the time.
June 9
The sun almost always (90 percent of the time) shines today, and there is a 15 percent chance for a high in the 90s, fifty percent chance for 80s, thirty percent for 70s and five percent for cold 60s. Thunderstorms come one year in three, but an all-day rain only one in 15.
June 10
This is typically one of the finest days in all of June, with rain and cloudy skies occurring just ten percent of the time. Fifteen percent of the afternoons are in the cool 60s - the last time for that considerable percentage until August 28th. Highs are in the mild 70s forty percent of the time, in the 80s twenty-five percent, in the 90s twenty percent.
June 11
There is a ten percent chance for a high in the 90s today, 55 percent for 80s, thirty percent for 70s, five percent for 60s. The sky is clear to partly cloudy eight years in ten, but rain comes 50 percent of the time. The morning is cool (in the 40s or 50s) two- thirds of the years, the last time the percentage is so high until September 15th.
June 12
A cold and rainy June 12th can occur once in a decade, and thunderstorms pass through half of all the years. But the sun still shines at least a little three days in four, and highs reach above 90 on 15 percent of the afternoons, are in the 80s fifty percent of the time, in the 70s thirty percent. About 100 frost-free days
remain in the growing season along much of the 40th Parallel.
June 13
Today, the 14th, and the 15th are the June days most likely to produce highs in the 90s (there's a 35 percent chance for 90s) and the 80s (a 45 percent chance of those). The remaining percentage falls to 70s. Skies are mostly clear to partly cloudy (completely overcast conditions come only 15 percent of the time), and rain falls just one day in four.
June 14
This is typically a hot day (40 percent chance of 90s, fifty percent for 80s, just ten percent chance for 70s), with a 90 percent chance of sun, and only a 15 percent chance for a passing thunderstorm. Cool mornings in the 50s occur just twice in a decade, making this the first time so far this year that the chances for lows in the 60s reach 80 percent.
June 15
Temperatures remain hot most of the time: four years in ten bring highs in the 90s, and five in ten bring 80s. Cool temperatures in the 70s or 60s share the remaining ten percent. The heat may contribute to making today one of the three June days most susceptible to a thunderstorm (the 2nd and the 20th are the other two). Rain falls 55 percent of the time. After the showers, the sky clears up eight years in ten.
June 16
Today is clear to partly sunny 90 percent of the time, with rain arriving only one day out of four. Today is also the first day of a three-day period on which relatively little precipitation occurs. Highs are typically in the middle 80s (65 percent chance), with hot 90s occurring 15 percent of the years, 70s fifteen percent, and cold 60s just five percent. After today, chances for a high below 70 drop to less than five percent (except for three scattered days in July and August) until the first week of September.
June 17
This is generally a mild day with a decent chance for a high in the cool 70s, the second greatest chance (50 percent) all month. Eighties come 40 percent of the time, 90s ten percent. Rain falls just one year in five on this date, and the sun appears nine years in a decade.
June 18
Ninety percent of June 18ths are without rain, and the sun appears 95 percent of the years. Temperatures are mild: in the 70s thirty percent of the time, in the 80s sixty-five percent of the time, with just a five percent chance for 90s. Evening lows are usually in the 60s, with cold 50s occurring 30 percent of the years.
June 19
Today is another sunny day (95 percent of all June 19ths are partly to mostly clear), but storms rise from the heat 35 percent of the time. Highs reach into the 80s fifty-five percent of all the years, and the chances for heat above 90 increase to 20 percent. Milder 70s come one year in four.
June 20
Rain occurs 55 percent of the time on June 20th, making this the day with the greatest likelihood for precipitation since June 2nd. Clouds completely cover the sky three years in ten. Chances for highs in the 90s rise to 25 percent; 80s come 35 percent of the years, 70s thirty percent, 60s just one year in ten. The odds for a cool night in the 40s or 50s remain steady at their mid-June level of three in ten.
June 21
Highs in the 60s occur five percent of the time on this date, 70s come on ten percent of the afternoons, 80s on 70 percent, and 90s on 15 percent. The sun appears nine years in ten, but thunderstorms pass through 30 percent of the time. Morning lows in the 40s come only five to ten percent of the time; 50s occur on 25 percent of the nights; 60 percent of the nights are in the 60s, and ten percent are in the 70s
June 22
Highs are in the 80s six years in ten, and 90s occur 25 percent of the time. Cool 60s or 70s are recorded 15 percent of the afternoons. Sun is the rule for this date, with only two years in a decade producing completely overcast conditions. Chances for precipitation, usually in the form of a thunderstorm: 35 percent. Lows stay above 60 tonight more often than on any other June night.
June 23
This is often a cooler day than the 22nd, due to the arrival of the fourth major high-pressure system of the month. The chances for a high in the 60s or 70s jump to 40 percent. Fifty-five percent of the time, however, highs reach into the 80s. Nineties come five percent of the time. The sun appears 85 percent of the days, but thunderstorms occur three times in a decade on this date.
June 24
Fifteen percent chance for a high in the 90s today, 55 percent for 80s, thirty percent for 70s. Most of the nights are in the 60s, but 40s are recorded ten to 15 percent of the time, and 50s fifteen to 20 percent. The sun almost always shines, and rain almost never falls on June 24th.
June 25
Chances for highs above 100 degrees today are five percent. Nineties come 15 percent of the afternoons, 80s seventy percent, and 70s just ten percent. Precipitation falls on only 15 percent of all June 25ths, making it one of the drier days of the entire year. The sun appears 95 percent of the time.
June 26
Like the 25th, today is typically sunny and dry, with no rain (just a five percent chance) or clouds likely. Highs are in the 90s twenty-five percent of the time, in the 80s sixty-five percent of the time, in the 70s just ten percent of the time. Sixty-five percent of the lows are in the 60s, thirty percent are in the 50s, and 40s occur five percent of the time.
June 27
The chances for precipitation jump suddenly from near zero to 30 percent. Sun, however, is still the rule, with completely overcast conditions occurring just 15 percent of the time. Highs are usually in the 80s (seven days out of ten), climb to 90 fifteen percent of the time, reach the 70s another 15 percent.
June 28
Temperature distribution for today: 20 percent chance for 90s, seventy percent for 80s, and ten percent for 70s. Skies are partly cloudy to sunny 80 percent of the days; precipitation, however, occurs 40 percent of the time as the final high-pressure system of the month approaches and the Corn Tassel Rains get underway. Those rains typically take place in a two-week period between the end of June and the middle of July.
June 29
The likelihood of precipitation is 35 percent, and clouds obscure the sky 25 percent of the days. The chance for a high in the 90s is 25 percent, for 80s fifty percent, for 70s twenty to 25 percent. This is one of only two middle-summer days when a cold afternoon in the 60s is possible (July 13th is the other).
June 30
Statistically, this is the coolest day of middle summer, recording a 55 percent chance for a high only in the 70s. The last time such odds occurred was June 4th. September 3rd will be the next time the chances return to 50 percent. Highs in the 80s occur 35 percent of the time, 90s fifteen percent. Chances for rain are good: 40 percent of June 30s bring a thunderstorm.