Climate · Hartford

Hartford, IL climate

Hartford has chilly winters and warm summers. A typical July afternoon reaches 88°, a January night drops to 23°, and about 11 inches of snow falls in a normal winter.

NOAA 1991-2020 climate normals Updated once a decade
July high
88°
104th hottest of 2,886 Illinois towns
January low
23°
321st mildest of 2,886 Illinois towns
Rain + melted snow
42 in
645th wettest of 2,886 Illinois towns
Snow a winter
11 in
393rd least snowy of 2,880 Illinois towns
A normal year

What a year in Hartford feels like

Winter

43° / 26°
Typical high / low · 4 days with an inch or more of snow

Spring

66° / 46°
Typical high / low · Last frost around Apr 4

Summer

87° / 67°
Typical high / low · 29 days reach 90° in a normal year

Fall

68° / 47°
Typical high / low · First frost around Nov 5
Best months to be outsideAprMaySepOctHighs of 62–84° and lows of 40° or more
Month by month

Hartford weather by month

Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.

MonthHighLowRain + meltSnowWet daysSnow on ground30-yr range
January40°23°2.5" 3.7"86 26° – 42°
February45°27°2.2" 2.5"83 26° – 45°
March56°36°3.4" 1.0"111 39° – 59°
April67°45°4.7" 0.1"110 49° – 62°
May77°56°5.0" 0130 61° – 74°
June85°65°4.3" 0100 70° – 79°
July88°69°4.2" 080 74° – 86°
August87°67°3.4" 090 71° – 83°
September80°58°3.3" 080 65° – 75°
October69°47°3.2" 090 53° – 64°
November55°36°3.4" 0.2"90 38° – 53°
December44°28°2.6" 3.3"84 22° – 44°
Year66°46°42.1"10.8"11215

“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.

Rain & snow

Rain and snow in Hartford

Hartford gets 42 inches of rain and melted snow a year. May is the wettest month and February the driest. Rain or snow falls on about 112 days a year. Snow covers the ground about 15 days of the year.

42 in
Rain + melted snow a year
More rain than 58% of U.S. towns
11 in
Snow in a normal winter
Less snow than 71% of U.S. towns
15 days
With 1"+ of snow on the ground
Fewer than 64% of U.S. towns

Rain + melted snow by month

Inches of water
5.0"

Snowfall by month

Inches of snow
3.7"
Frost & the growing season

About 214 frost-free days a year

In half of years the last 32° night comes by April 4 and the first one by November 5. That leaves about 214 frost-free days for gardens, longer than 80% of U.S. towns.

85
nights at or below 32° in a normal year
1
nights below 0° in a normal year
29
days that reach 90° in a normal year

Freezing nights by month

Average nights at or below 32°

90° days by month

Average days at 90° or more
Heating & cooling

Heating and cooling a home in Hartford

Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Hartford, 77% of that work is heating and 23% is cooling.

77%heating
4,780 heating degree daysLess heating than 70% of U.S. towns
1,424 cooling degree daysMore cooling than 76% of U.S. towns

Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.

Around Hartford

Hartford and its neighbors

Hartford borders 5 towns with climate data. January nights across them vary by 0.4°. Wood River has the coldest January nights (23°) and Madison the hottest July afternoons (89°). Hartford’s January low is 23° and its July high 88°.

Wood River: January low 23°, July high 88°Fort Russell: January low 22°, July high 88°Granite City: January low 23°, July high 89°Nameoki: January low 23°, July high 89°Pontoon Beach: January low 23°, July high 89°Venice: January low 23°, July high 89°Chouteau: January low 23°, July high 89°Rosewood Heights: January low 23°, July high 88°East Alton: January low 23°, July high 88°Bethalto: January low 23°, July high 88°Edwardsville: January low 23°, July high 88°Fairmont City: January low 23°, July high 89°Venice: January low 23°, July high 89°Brooklyn: January low 24°, July high 89°Roxana: January low 23°, July high 88°Granite City: January low 23°, July high 89°Wood River: January low 23°, July high 88°South Roxana: January low 23°, July high 88°Madison: January low 23°, July high 89°Hartford: January low 23°, July high 88° HartfordRoxanaGranite CityWood RiverSouth RoxanaMadison
ColderMilder22° to 24°
Wood River22.8° −0.2°
Hartford23.0°
Roxana23.0° same
South Roxana23.0° same
Granite City23.2° +0.2°
Madison23.2° +0.2°

Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.

Compared with other towns

How Hartford compares

Summer heat88° July high
Hotter than 73% of U.S. towns104th hottest of 2,886 Illinois towns
Winter cold23° January low
Milder than 67% of U.S. towns321st mildest of 2,886 Illinois towns
Precipitation42" a year
Wetter than 58% of U.S. towns645th wettest of 2,886 Illinois towns
Snow11" a winter
Less snow than 71% of U.S. towns393rd least snowy of 2,880 Illinois towns
Growing season214 frost-free days
Longer than 80% of U.S. towns11th longest of 2,886 Illinois towns

Compared with every U.S. town and city on TownTapestry, each counted once.

Then and now

Warmer than it used to be

+0.9°1991–2020 average vs. the 20th century (1901–2000)

The last 30 years in Hartford averaged 0.9° warmer than the 1900s. The biggest change is in December (+2.1°). The shift is smaller than in 77% of U.S. towns.

❄️ Winter+1.7° now 34°, was 33°
🌷 Spring+1.2° now 56°, was 55°
☀️ Summer+0.3° now 77°, was 77°
🍂 Fall+0.4° now 58°, was 57°

Change by month1991–2020 average minus 1901–2000 average, at Hartford’s spot on NOAA’s grid

Year to year

How much a month can swing

A normal is an average, and real years wander around it. December swings the most: between 1991 and 2020 its average temperature ranged from 22° to 44°. June is the most reliable, staying within 9°.

Coldest to warmest month in 30 yearsNormal
Questions

Common questions about Hartford’s climate

What is the coldest month in Hartford?

January, with a typical high of 40° and a low of 23°.

What is the hottest month in Hartford?

July, with a typical high of 88° and a low of 69°. About 29 days a year reach 90°.

How much snow does Hartford get?

About 11 inches in a normal winter, most of it in January.

When is the first frost in Hartford?

In half of years the first 32° night comes by November 5, and the last spring frost by April 4.

What is the rainiest month in Hartford?

May, with 5.0 inches of rain and melted snow. The year totals 42 inches.

Temperatures and rainfall come from NOAA’s gridded climate normals for Hartford itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Edwardsville 2 W, IL (5 mi, snow) and Alton - Melvin Price L&d, IL (5 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.

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