The November Outlook
November's average temperatures fall one degree every 50 hours, finding the middle 30s by the end of the month. Normal highs slip down to 44 and lows dip to 29 by December 1st. With averages plummeting a total of 14 degrees, around 15 mornings below freezing occur in the next 30 days.
There is an average of only one or two days in the 70s, just six in the 60s and only eight in the 50s. That makes just half the month with moderate afternoons, and many of those fall within a week of All Saints Day (November 1st). The coldest days in November, those with better than a 35 percent chance of a high below 40 degrees, are the 12th, 13th, 15th, 18th, 21st, 24th, 28th, 29th, and 30th. The days with the best chances for highs in the 60s and 70s are usually the 1st through the 4th.
In the entire month of November, five to six completely clear days can be expected, ten or eleven partly cloudy days, and about 13 mostly or completely cloudy ones. Odds are even that most of the warmer days will be cloudy. The sky becomes especially gray after the 14th of the month, the solar pivot time when the Midwest darkens until May, and the percentage of sunshine in an average day drops from 60 percent to 40 percent.
Overcast skies are likely to bring a steady rain 11 out of the next 30 days. Snow or sleet is ordinarily recorded on between one and four occasions before December 1st, the first snow almost always arriving between the 10th and the 20th.
The darkest November days, those with just a 15 to 30 percent chance for sun, are the 15th, the 23rd, and the 28th. The rainiest periods of the month are usually between the 1st and the 5th, the 9th and the 11th, the 15th and the 17th, the 25th through the 29th, each carrying at least a 35 percent chance of precipitation. Of those days, the 5th, 9th, 15th, 20th, 23rd, 26th, and especially the 27th are the wettest of all. Odds for snow are best on the 28th, 29th, and 30th. The driest days for harvest are typically the 8th, the 13th, the 18th, and the 21st, each with only a 15 percent chance for rain or snow.

Autumncount
Eighteen major weather systems cross the United States in a midwestern autumn. Four of those fronts arrived in September, six in October. Seven additional cold waves, most of them accompanied by precipitation, cross the Mississippi in the next 30 days (the final Autumncount front coming on December 3rd). Mild conditions are common until the first weather system arrives.

Front 11 – November 2: As November arrives, frost often moves into the Border States, and the odds increase for cold throughout the week ahead. The 3rd ushers in the snow season for the nation’s midsection, flurries or accumulation becoming at least a ten percent possibility per day between that date and spring. Chances for a thunderstorm virtually disappear until February in the Midwest, but all-day rains increase. On the other hand, if this first November front is a day or two late, the 1st through the 3rd or 4th can be some of the mildest days of late autumn.

Front 12– November 6: This weather system usually brings the coldest days of November’s first week. It also carries middle fall into the Border States and the South, late fall to the Midwest and southern Plains, and early winter to farms along the Canadian border. The days immediately after the November 6th front are usually much more moderate, but precipitation is the rule as the next system approaches. Beginning at this time of month, the percentage of daily sunlight drops quickly, and the wind blows a little harder, rising to its winter levels.

Front 13 – November 11: Sun often follows this front, and the 11th, 12th and 13th are often some of the best days in the first half of the month for harvest. A dramatic increase in the number of freezing predawn temperatures starts with this system, the lows below 32 growing from a frequency average of 40 percent up to 70 percent across the nation’s midsection.

Front 14 – November 16: As this front approaches, expect milder conditions, but an increased chance for rain or snow. Although the November 16th system can be relatively gentle, sometimes it brings highs only in the teens or even 20s as far south as Kentucky. After the front moves through, favorable harvest conditions typically follow: the 18th is one of the drier November days in the Midwest, the 17th in the Plains, the 19th in the East.

Front 15 – November 20: The cycle of the November 20th weather system causes milder conditions before its arrival and increased chances for precipitation. This is a front that carries up to two or more inches of snow across the North four years in a decade. After the system comes through, it can be followed by single digits in the North, and a hard freeze deep into the South.

Front 16 – November 24: This sixth cold front of the month, arriving around the 24th, often brings rain or significant snowfall as it passes through. After the 25th, the percentage of cloudy days almost doubles over the average for the rest of November; even in the South, overcast conditions begin to increase the likelihood for seasonal affective disorders and contribute to complications with harvest. This weather system marks the decline of average highs below 50 degrees and the end to any reasonable chance of a day above 70 throughout the Midwest and Mid-Atlantic states. Average low temperatures fall below freezing throughout the North. As the final weather system of the month approaches, however, the 26th is sometimes one of the windiest and mildest days in late November.

Front 17 – November 28: The seventh high-pressure system of November generally arrives around the 28th, preceded by rain or snow three years out of four. This is one of the most dangerous weather systems of the month, and precipitation lingers through the cold for the 29th and 30th. Clouds dominate the sky, and travel conditions are typically uncertain. The weather ordinarily moderates around the last day of November, setting the stage for an early December thaw.

Frostwatch
The following chart shows the chances that frost will have struck your plants by the date indicated. Calculations are based on average frequency of freezing temperatures in central Ohio and Indiana during the month of September. The data can be adjusted by adding five percent for each 100 miles north of the 40th parallel. Subtract five percent for each 100 miles south of the 40th parallel.

Date Chance for Light Frost Chance for Killing Frost
November 1: 100 percent 80 percent
November 10: 90 percent
November 20: 95 percent
November 25: 100 percent

WEEKLY WEATHER

WEEK 1
The chances for warmth in the 70s drop to just five percent on November 4th, and odds increase for cold throughout the week ahead. Highs just in the 30s or 40s were relatively rare during the final days of October, but by the 5th of November, they occur 25 percent of the time, and chances rise to over 40 percent by the 10th of the month.
The coolest days in this period are typically the 6th and the 7th, both of which have only about a 15 percent chance for warmth in the 60s. The 3rd ushers in the snow season for the central states, flurries or accumulation emerging into the realm of possibility, at least a ten percent possibility per day between that date and spring.
Chances for a thunderstorm virtually disappear until February in the lower Midwest, but all-day rains increase. The first ten days of November are about twice as rainy as the final ten of October. Chances for rain or snow run at about 40 percent from the 1st through the 5th, then drop to just 25 percent on the 6th, 7th, and 8th.

WEEK 2
Late fall almost always arrives in the second week of November. It is a transition season during which the last leaves fall, skies darken, wind speed increases, hard frosts put and end to the year's flower and vegetable cycles, harvest is completed on the farm, and final preparations for winter are made.
Late fall's high temperatures shift decidedly into the 40s, and lows average 32 or worse. High-pressure systems, accompanied by clouds and rain or snow, typically arrive around the 9th and the 14th. The 9th is historically the wettest day of November's second week. The 11th and 12th are the sunniest, and the 13th is the driest. At least one partly cloudy afternoon in the 60s or 70s comes six years out of ten during this time of the year, but cold and precipitation are the norm. Heating degree days are now more than double those of October.

WEEK 3
The 15th, 19th, and 20th are the days this week most likely to be mild with highs in the 60s. The fifth cold front of the month comes through at the end of the period, however, and the 21st brings a slight possibility for a high only in the 20s. The 15th is the day most likely to bring precipitation, having a 60 percent chance for rain or snow. The 20th is also fairly damp, carrying a 50 percent chance. The 18th is the driest day of the week; it has only a 20 percent chance for showers or flurries.

WEEK 4
The fourth week of November, the third week of late fall, is the stark and windy week that marks the decline of average highs below 50 degrees and the end to any reasonable chance of a day above 70 throughout the lower Midwest and Mid-Atlantic states. Nights below zero even become possible. The sixth cold front of the month, arriving around the 24th, often brings rain on the 23rd (there is a 50 percent chance of that). The seventh high-pressure system generally arrives on November 28th, preceded by rain 70 percent of the time on the 27th—the wettest day in the month’s weather history. November 28th, 29th, and 30th have the best odds of the month for snow. After the 25th, the percentage of cloudy days almost doubles over the average for the rest of November.