Climate and average weather in Farmington

In Farmington, the summers are humid, hot, showery, and partly cloudy and the winters are cold, snowy, and partly cloudy.

Best: early September to late October

Over the course of the year, the temperature in Farmington typically varies from 26°F to 87°F, and is rarely below 8°F or above 95°F. July is the hottest month of the year, while January is the coldest.

Based on the travel score, the best times of year to visit Farmington for warm-weather activities are from early May to early June and early September to late October.

Hottest
Jul
87°
Coldest
Jan
26°
Wettest
Apr
5.0 in
Driest
Feb
2.7 in
Rain / yr
42.8 in
118 wet days
Daylight
9.4–14.6 h
shortest–longest
Elevation
912 ft
37.8°N
Clearest
Sep
46% cloud

Farmington is city in and county seat of St. Francois County, Missouri, United States.

Density
764/km²
people per km²
Founded
1822

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Farmington weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around early September to late October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Farmington, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 4.1 months, from May 22 to September 24, with daily high temperatures above 76°F. The hottest month of the year in Farmington is July, with an average high of 87°F and low of 69°F.

The cool season lasts 3.0 months, from November 28 to February 27, with daily high temperatures below 50°F. The coldest month of the year in Farmington is January, with an average low of 26°F and high of 41°F.

Days typically run about 18°F warmer than nights year-round.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan4126
Feb4629
Mar5637
Apr6647
May7457
Jun8366
Jul8769
Aug8667
Sep7959
Oct6748
Nov5537
Dec4429

How hot and cold Farmington really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the hottest afternoons, once humidity is folded in, Farmington feels like about 91°F (around July 15). About 20 days a year carry some heat stress, peaking in July.

On the coldest nights, wind chill pulls the feels-like down to about 17°F (around January 14), with roughly 123 freezing days a year (feels-like at or below 32°F), worst in January.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°F)Air high (°F)Feels-like low (°F)Air low (°F)
Jan41411726
Feb46462129
Mar56563137
Apr66664447
May74745757
Jun84836666
Jul90876969
Aug87866767
Sep79795959
Oct68674548
Nov55553237
Dec44442229

Average hourly temperature in Farmington

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on July afternoons, near 87°F, and coldest before dawn in January, near 26°F.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Farmington weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan41° / 26°2.88.22.69.70.1
Feb46° / 29°2.77.62.610.51.3
Mar56° / 37°4.011.21.411.73.7
Apr66° / 47°5.011.70.112.95.8
May74° / 57°4.913.20146.3
Jun83° / 66°3.711.6014.65.5
Jul87° / 69°3.511.3014.34.6
Aug86° / 67°3.09.8013.55.2
Sep79° / 59°3.28012.37.1
Oct67° / 48°3.48.40116.6
Nov55° / 37°3.68.70.6103.6
Dec44° / 29°2.88.11.99.40.9

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Farmington gets about 42.8 in of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.

The wetter season lasts 5.2 months, from around Mar 10 to Aug 13, peaking in May at about 44% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Oct 3.

April is the wettest month by volume, with 5.0 in over about 12 wet days; February is the driest, with 2.7 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%60%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetMay 1 · 44%Oct 3 · 23%
Rain on a day (%)Rain days
Jan268
Feb288
Mar3511
Apr4012
May4213
Jun3912
Jul3611
Aug3110
Sep278
Oct278
Nov299
Dec278

Monthly rainfall

Over a full year, Farmington collects about 42.8 in of rain across 118 wet days — roughly 3.6 in in an average month.

It doesn’t fall evenly. April is the wettest month with 5.0 in, while February is the driest at just 2.7 in. The three wettest months alone bring about 33% of the year’s total, and some of the cold-season precipitation falls as snow.

0123456JanFebMarAprMayJunJulAugSepOctNovDec2.82.74.05.04.93.73.53.03.23.43.62.8
Rainfall (in)Rain daysSnow days
Jan2.883
Feb2.783
Mar4.0111
Apr5.0120
May4.9130
Jun3.7120
Jul3.5110
Aug3.0100
Sep3.280
Oct3.480
Nov3.691
Dec2.882

Snow in Farmington

Average snowy days through the year, the snow-season span, and estimated snowfall — for ski trips and the perennial 'will there be snow at Christmas?' question.

Farmington averages about 9 snowy days a year. Snow season runs roughly Nov 10 to Mar 30 — about 4.6 months.

February is snowiest, with roughly 3 days of snow and an estimated 6 in of snowfall. Over the year that adds up to an estimated 19 in of snow.

0246JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonFeb 6
Snow daysSnowfall (in)
Jan35
Feb36
Mar13
Apr00
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov11
Dec24

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Farmington, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.

The clearer part of the year begins around June 11 and lasts for 5.4 months, ending around November 20. The clearest month is September, when the sky is clear, mostly clear, or partly cloudy 63% of the time on average.

The cloudier part of the year begins around November 21 and lasts for 6.6 months, ending around June 10. The cloudiest month is February, when it is overcast or mostly cloudy 60% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecOct 1 · 66%Feb 14 · 38%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan4456
Feb4060
Mar4456
Apr4555
May4258
Jun5149
Jul5545
Aug6040
Sep6337
Oct5941
Nov5050
Dec4357

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 11, brings about 14 h 36 min of light; the shortest, around January 1, only 9 h 24 min — a swing of roughly 5 h 12 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.77:215:01
Feb10.57:005:33
Mar11.76:206:02
Apr12.95:336:31
May14.04:576:59
Jun14.64:447:20
Jul14.34:567:19
Aug13.55:226:50
Sep12.35:496:03
Oct11.06:175:17
Nov10.06:494:45
Dec9.47:164:40

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Farmington averages about 11 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 8 and 16 days.

The sunnier stretch runs 4.2 months, from around Jul 28 to Dec 1. The sunniest month is October, with roughly 14 sunny days (mixed).

The greyest month is May, down near 8 sunny days — about 42% fewer than the October peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightOct 116 daysMay 268 days
Sunny daysSky
Jan10Mixed
Feb8Mixed
Mar10Mixed
Apr9Mixed
May8Mixed
Jun10Mixed
Jul11Mixed
Aug12Mixed
Sep14Mixed
Oct14Mixed
Nov12Mixed
Dec10Mixed

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Farmington, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 4.6 months, from around May 10 to September 26. The muggiest month is July, when the air feels humid, muggy or worse about 84% of the time.

The most comfortable stretch runs from around September 27 to May 9, and January is the most comfortable month — the air is dry or comfortable 100% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJan 7 · 100%Jul 16 · 14%oppressivemuggyhumiddrycomfortablecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan9910000
Feb9910000
Mar9631000
Apr80136000
May4518211610
Jun13152236150
Jul4121732331
Aug8152132240
Sep3619192150
Oct77128300
Nov9442000
Dec9820000

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Farmington is typically calm, near 7 mph, and varies moderately with the seasons.

The windier part of the year lasts 7.1 months, from around Oct 12 to May 16. The windiest month is April, averaging about 8 mph (light breeze).

The calmer part of the year runs from around May 17 to Oct 11, with August the calmest month at about 5 mph.

051015JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezyApr 11 · 8 mphAug 3 · 5 mph
Wind speed (mph)Feels
Jan8light breeze
Feb8light breeze
Mar8light breeze
Apr8light breeze
May7calm
Jun6calm
Jul5calm
Aug5calm
Sep6calm
Oct7calm
Nov8light breeze
Dec8light breeze

Best time to visit Farmington

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Farmington throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around mid October, Farmington is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 64°F and 82°F. Based on this score, the best times of year to visit Farmington for general outdoor tourist activities run from early May to early June and again from early September to late October, with a peak score in the last week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationSep 29 · 7.6

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan0.1poor
Feb1.3poor
Mar3.7fair
Apr5.7good
May6.2good
Jun5.5good
Jul4.6fair
Aug5.2fair
Sep7.0good
Oct6.6good
Nov3.6fair
Dec0.9poor

The beach/pool score favors clear, rainless days with daytime highs between 75°F and 93°F. Based on this score, the best time of year to visit Farmington for hot-weather activities is from late May to early October, with a peak score in the last week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 29 · 7.3

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Farmington, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around July (highs near 87°F), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 41°F), pack a warm layer, a heavy coat and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Farmington sees daytime highs around 87°F and nights near 69°F. Pack light clothes and sun protection. Worth having: rain gear. About 11 days see rain.

UV index (midday) in Farmington by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Farmington peaks around June 21 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateJun 21UV 10Dec 23UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar6High
Apr7Very high
May8Very high
Jun10Very high
Jul9Very high
Aug8Very high
Sep7High
Oct4Moderate
Nov4Moderate
Dec2Moderate

Average hourly UV index in Farmington

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in June the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 6 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan00
Feb30
Mar5.50
Apr73.5
May84.5
Jun8.56
Jul85.5
Aug7.54.5
Sep6.52.5
Oct40
Nov2.50
Dec00

Air quality in Farmington by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in Farmington is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.9× the cleanest month (November, 6 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1316 µg/m³Nov 176 µg/m³
PM2.5 (µg/m³)Level
Jan6Good
Feb9Good
Mar11Good
Apr9Good
May12Good
Jun14Moderate
Jul16Moderate
Aug12Moderate
Sep10Good
Oct6Good
Nov6Good
Dec6Good
Almanac & agriculture

Growing season

Chance of a frost-free dayTypical season (≥50%)

The growing season in Farmington typically lasts about 278 days, from around March 1 to December 3 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 10 to October 25.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonMar 150%Apr 1090%Oct 2590%Dec 350%
Frost-free chance (%)Frost nights
Jan2831
Feb3828
Mar7031
Apr936
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct944
Nov7130
Dec4031

Growing degree days

Degree days (base 50°F)Frost-free shaded

Growing degree days tally heat above 50°F: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Farmington banks about 3,914 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

01,0002,0003,0004,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°F·days)
Jan0
Feb0
Mar6
Apr197
May483
Jun736
Jul875
Aug815
Sep565
Oct236
Nov2
Dec0

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Farmington receives about 4.3 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 2.0 and 6.5 kWh/m².

The brighter stretch of the year lasts 6.3 months, from around Mar 22 to Sep 29. The brightest month is June, averaging about 6.4 kWh/m² (intense).

The dimmest month is December, down near 2.0 kWh/m² — roughly 69% less than the June peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJun 246.5 kWhDec 182.0 kWh
Solar energy (kWh/m²)Level
Jan2.3Moderate
Feb3.1Moderate
Mar4.2Bright
Apr5.2Bright
May5.8Bright
Jun6.4Intense
Jul6.3Intense
Aug5.8Bright
Sep4.8Bright
Oct3.6Moderate
Nov2.5Moderate
Dec2.0Dim

Where is Farmington?

Farmington sits at 37.8°N, 90.4°W, 912 ft above sea level, in United States. The nearest listed city is Arnold, 45 mi away.

Topography around Farmington

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Farmington.

Within 2 miles, the terrain around Farmington has only modest variations in elevation — a maximum elevation change of 361 ft around an average of 922 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,014 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,562 ft.

The land around Farmington is covered by grassland (42%) and trees (34%) within 2 miles, trees (63%) and grassland (31%) within 10 miles, and trees (73%) within 50 miles.

2 miles
361 ft
10 miles
1,014 ft
50 miles
1,562 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
Nearby: Arnold 45 mi · Oakville 48 mi · Mehlville 50 mi · Concord 52 mi · Lemay 53 mi · Affton 53 mi · Kirkwood 55 mi · Webster Groves 56 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Farmington (37.7809°, -90.4218°, elevation 912 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).