Photo: formulanone from Huntsville, United States · CC BY-SA 2.0Nights turn raw in Farmington each January, colder than in 80% of U.S. towns
High summer brings afternoon highs near 85°. It is a dry place: less rain and snow fall here than on 64% of U.S. towns. Warming shows here too: 1.0° more than in 1901–2000, led by December. Tender plants can go out after about April 16; in half of years the first frost comes by October 23.
A year in Farmington at a glance
Each month’s typical high and low, and what it brings.
What stands out about Farmington’s climate
Compared with towns across the U.S., with Farmington’s place in Illinois beside it.
What a year in Farmington feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 189 frost-free days a year
In half of years the last 32° night comes by April 16 and the first by October 23. Frost and day counts come from NOAA’s station at Peoria Gtr Peoria Airport, 17 miles from the town’s center, at about the same height.
The 2023 USDA map puts Farmington’s center in zone 5b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −11°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 21 inches of snow a winter
Snow, measured at Yates City, IL, falls mostly in January, February and December. Precipitation (rain plus melted snow) adds up to 39 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 109 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Farmington
83% of the work is heating. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Peoria Gtr Peoria Airport.
Living with Farmington’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
189 frost-free days in zone 5b. The last frost comes by Apr 16 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 23.
Months with highs of 62–84° and lows of 40° or more: April, May, June, August, September and October. 0.2 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Farmington from natural hazards, river flooding is the largest share (38%); heat waves, cold waves, winter storms and ice storms together are 30%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Farmington and similar climates
TownRatings has no climate map of the towns around Farmington yet.
Climates most like Farmington’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Farmington, IL | 16° | 85° | 39" | 21" |
| Centerville, IA | 15° | 85° | 38" | 22" |
| Lafayette, IN | 18° | 84° | 40" | 21" |
| Defiance, OH | 19° | 85° | 37" | 24" |
| Savannah, MO | 18° | 87° | 37" | 21" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Farmington averaged 1.0° warmer than the 1900s. The biggest change is in December (+2.2°).
A smaller shift than in 77% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Farmington compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Farmington’s place among Illinois’.
Farmington weather by month
Highs, lows and precipitation from NOAA’s grid at Farmington’s center; snow, wet days and snow on the ground from Yates City, IL. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 32° | 16° | 1.9" | 6.0" | 8 | 14 | 17° – 36° |
| February | 37° | 21° | 1.9" | 5.9" | 8 | 9 | 17° – 40° |
| March | 50° | 30° | 2.5" | 2.8" | 9 | 4 | 33° – 54° |
| April | 63° | 40° | 3.9" | 0.4" | 10 | 0 | 44° – 59° |
| May | 74° | 52° | 5.1" | 0.0" | 14 | 0 | 57° – 71° |
| June | 82° | 61° | 4.6" | 0.0" | 11 | 0 | 68° – 76° |
| July | 85° | 65° | 4.1" | 0.0" | 9 | 0 | 70° – 81° |
| August | 84° | 62° | 3.5" | 0.0" | 8 | 0 | 67° – 78° |
| September | 78° | 54° | 3.7" | 0.0" | 7 | 0 | 60° – 71° |
| October | 65° | 43° | 3.1" | 0.1" | 10 | 0 | 49° – 59° |
| November | 50° | 32° | 2.6" | 0.7" | 7 | 1 | 33° – 50° |
| December | 37° | 22° | 2.1" | 5.4" | 8 | 8 | 15° – 40° |
| Year | 61° | 41° | 39.0" | 21.3" | 109 | 36 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 15° to 40°. June is the most reliable, staying within 8°.
Where Farmington’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Farmington’s center.
- Snow: Yates City, IL.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Peoria Gtr Peoria Airport, 17 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Farmington’s climate
What is the weather like in Farmington?
A typical July afternoon reaches 85°, a January night drops to 16°, and about 21 inches of snow falls in a normal winter. Colder January nights than 80% of U.S. towns; hotter July afternoons than 51% of U.S. towns.
How cold does it get in Farmington in winter?
January nights average 16°. About 118 nights a year reach 32° or below and 6 reach 0° or below. In the coldest January of the last 30 years the month averaged 17°.
How much snow does Farmington get?
About 21 inches in a normal winter at Yates City, IL, most of it in January, February and December, with snow on the ground about 36 days a year.
How hot does it get in Farmington?
July, with a typical high of 85° and a low of 65°. About 23 days a year reach 90° (Peoria Gtr Peoria Airport).
When is the first and last frost in Farmington?
In half of years the last spring frost (32°) comes by April 16 and the first fall frost by October 23, about 189 frost-free days, at Peoria Gtr Peoria Airport.
What growing zone is Farmington in?
Zone 5b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −11°.
What is the best time of year to visit Farmington?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June, August, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Farmington getting warmer?
Yes: 1991–2020 averaged 1.0° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 77% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Farmington.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.