Barrington, Illinois climate: Normal weather by month, frost dates and records
Barrington's normal year runs from 13°F January nights to 81°F July afternoons, with 40.4 inches of precipitation and 39 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.9°C, January lows of −10°C, July highs of 27°C, 1,027 mm of precipitation a year.
- NOAA stationBarrington (3 mi SW)
- Station IDUSC00110442
- Location42.12°N 88.16°W
- Elevation875 ft (267 m)
- Population10,615
On October 23, the normal high in Barrington is 57°F and the normal low 39°F, and the chance of measurable rain or snow is 36%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Barrington.
- Jan 29° 13°
- Feb 33° 16°
- Mar 45° 27°
- Apr 58° 37°
- May 69° 48°
- Jun 78° 58°
- Jul 81° 63°
- Aug 79° 61°
- Sep 72° 54°
- Oct 60° 42°
- Nov 46° 30°
- Dec 34° 20°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Barrington each month?
July is the warmest month, with normal highs of 81°F; January the coldest, with normal lows of 13°F. The most precipitation falls in May (5.15 in), the least in February (1.90 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 29°F | 13°F | 21.1°F | 2.07 | 12.6 | 10 | <1 | 29 | 9 h 30 min |
| February | 33°F | 16°F | 24.6°F | 1.90 | 8.5 | 9 | <1 | 27 | 10 h 30 min |
| March | 45°F | 27°F | 35.5°F | 2.35 | 4.6 | 10 | <1 | 22 | 11 h 50 min |
| April | 58°F | 37°F | 47.3°F | 3.95 | 1.1 | 13 | <1 | 8 | 13 h 20 min |
| May | 69°F | 48°F | 58.4°F | 5.15 | 0.0 | 14 | <1 | <1 | 14 h 30 min |
| June | 78°F | 58°F | 67.8°F | 4.60 | 0.0 | 13 | 1 | <1 | 15 h 10 min |
| July | 81°F | 63°F | 72.0°F | 4.02 | 0.0 | 10 | 3 | <1 | 15 h |
| August | 79°F | 61°F | 70.2°F | 4.58 | 0.0 | 11 | 2 | <1 | 14 h |
| September | 72°F | 54°F | 63.0°F | 3.65 | 0.0 | 10 | <1 | <1 | 12 h 30 min |
| October | 60°F | 42°F | 50.8°F | 3.39 | 0.1 | 11 | <1 | 5 | 11 h 10 min |
| November | 46°F | 30°F | 38.2°F | 2.58 | 2.0 | 11 | <1 | 18 | 9 h 50 min |
| December | 34°F | 20°F | 27.0°F | 2.19 | 9.6 | 11 | <1 | 28 | 9 h 10 min |
| Year (annual) | 57°F | 39°F | 48.0°F | 40.43 | 38.5 | 131 | 6 | 137 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −2°C | −10°C | −6.1°C | 53 mm | 32 cm |
| February | 0°C | −9°C | −4.1°C | 48 mm | 22 cm |
| March | 7°C | −3°C | 1.9°C | 60 mm | 12 cm |
| April | 14°C | 3°C | 8.5°C | 100 mm | 3 cm |
| May | 20°C | 9°C | 14.7°C | 131 mm | 0 cm |
| June | 25°C | 15°C | 19.9°C | 117 mm | 0 cm |
| July | 27°C | 17°C | 22.2°C | 102 mm | 0 cm |
| August | 26°C | 16°C | 21.2°C | 116 mm | 0 cm |
| September | 22°C | 12°C | 17.2°C | 93 mm | 0 cm |
| October | 16°C | 5°C | 10.4°C | 86 mm | 0 cm |
| November | 8°C | −1°C | 3.4°C | 66 mm | 5 cm |
| December | 1°C | −7°C | −2.8°C | 56 mm | 24 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00110442; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Barrington?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (10).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00110442.
When is the last frost in Barrington?
In Barrington, the last spring frost (32°F) comes after April 25 in half of years and after May 12 in one year in ten; the first autumn frost comes before October 19 in half of years and before October 5 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 251 year in 10 after May 12; 9 in 10 after April 10
- First autumn frost, half of years before
- October 191 year in 10 before October 5; 9 in 10 before November 1
NOAA puts the median frost-free season at 177 days, and the season without a hard freeze (28°F) at 200 days.
A hard freeze (28°F) comes after April 12 in half of springs and before October 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Barrington in zone 5b in ZIP code 60010, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Barrington's NOAA station is in zone 5b: the coldest night of a typical year reaches −12°F (21 complete years).
Frost dates for every NOAA station in Illinois · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00110442; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Barrington?
In a normal year in Barrington, 6 days a year reach 90°F, 137 nights fall to 32°F or colder and 131 days bring measurable precipitation.
- Days at 90°F or more
- 6a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 137a normal year
- Days that stay below freezing
- 54high of 32°F or less
- Days with 0.01 inch of precipitation
- 131a normal year
- Days with 1 inch of snow or more
- 13a normal year
The highest temperature in this station's record (since 1962) is 103°F, on July 10, 1974; the lowest is −28°F, on January 31, 2019.
The wettest calendar year on that record is 2018, with 54.33 in; the snowiest season is 1978–79, with 72.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00110442; records: ACIS (NOAA Regional Climate Centers), station USC00110442. Records use complete months only; a month missing more than three days is left out.
How sunny is Barrington?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Barrington, 3.9 kWh per square metre a day. July is the sunniest month (80%) and December the cloudiest (61%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 63% | 1.7 |
| February | 67% | 2.6 |
| March | 67% | 3.6 |
| April | 69% | 4.7 |
| May | 70% | 5.5 |
| June | 76% | 6.1 |
| July | 80% | 6.3 |
| August | 79% | 5.4 |
| September | 78% | 4.3 |
| October | 69% | 2.8 |
| November | 66% | 1.9 |
| December | 61% | 1.4 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Barrington need?
A normal year in Barrington brings 6,816 heating degree days, 27% more than the median U.S. place (5,373), and 652 cooling degree days, 28% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,764 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,362 | 0 |
| February | 1,131 | 0 |
| March | 916 | 1 |
| April | 533 | 4 |
| May | 244 | 39 |
| June | 53 | 137 |
| July | 9 | 224 |
| August | 14 | 175 |
| September | 127 | 67 |
| October | 446 | 6 |
| November | 803 | 0 |
| December | 1,180 | 0 |
| Year (annual) | 6,816 | 652 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00110442. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Barrington been warmer than normal lately?
2025 averaged 48.9°F, 0.9°F above the 1991-2020 normal of 48.0°F. 4 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 49.7°F | +1.7°F | 28.37 | 37.2 |
| 2023 | 50.2°F | +2.2°F | 31.34 | 20.1 |
| 2024 | 51.6°F | +3.6°F | 34.96 | 23.8 |
| 2025 | 48.9°F | +0.9°F | 30.21 | 35.0 |
Over 35 complete years from 1963 to 2025, the station's annual mean temperature rose at a fitted 6.1°F per century (+0.34°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00110442; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Barrington's climate compare?
Barrington is warmer than 8 of the other 143 places with their own NOAA record in Illinois, and wetter than 80. Across the 7,247 U.S. stations with normals, its annual mean of 48.0°F is warmer than 32%.
In the Köppen classification computed from these normals, Barrington is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Barrington share this climate record?
7 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Palatine, ILalso near: Wheeling (7 mi, 50.8°F a year); Streamwood (9 mi, 49.6°F a year)65,951 people · 6 mi E
- Inverness, IL7,428 people · 3 mi E
- South Barrington, IL5,061 people · 2 mi S
- Fox River Grove, IL4,747 people · 6 mi NW
- Barrington Hills, IL4,080 people · 3 mi NW
- Deer Park, IL3,669 people · 5 mi NE
- Trout Valley, IL507 people · 7 mi NW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Barrington's climate
What is the coldest month in Barrington?
January, with a normal high of 29°F and a normal low of 13°F. The warmest is July (81°F by day, 63°F at night).
Does it snow in Barrington?
Yes: 39 inches in a normal year, falling on 25 days with 0.1 inch or more, the most in January (12.6 inches).
What is the rainiest month in Barrington?
May, with 5.15 in of precipitation in a normal year; the driest is February with 1.90 in.
What plant hardiness zone is Barrington in?
The USDA's 2023 map puts Barrington in zone 5b in ZIP code 60010, the nearest ZIP area. By the same method at Barrington's NOAA station, the coldest night of a typical year reaches −12°F (21 years, 1991-2020): zone 5b.
How late can frost come in Barrington?
In half of years the last 32°F night comes after April 25; in one year in ten it comes after May 12. Waiting until May 12 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Streamwood, IL6 miles from this station, 49.6°F a year
- Elgin, IL7 miles from this station, 49.0°F a year
- Mundelein, IL11 miles from this station, 47.9°F a year
- Wheeling, IL13 miles from this station, 50.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made