Chicago Botanic Garden, Illinois climate: Climate normals at a NOAA weather station
Chicago Botanic Garden's normal year runs from 16°F January nights to 84°F July afternoons, with 39.5 inches of precipitation and 34 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.8°C, January lows of −9°C, July highs of 29°C, 1,004 mm of precipitation a year.
- NOAA stationChicago Botanic Garden
- Station IDUSC00111497
- Location42.14°N 87.79°W
- Elevation630 ft (192 m)
On October 23, the normal high in Chicago Botanic Garden is 60°F and the normal low 40°F, and the chance of measurable rain or snow is 35%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Chicago Botanic Garden.
- Jan 32° 16°
- Feb 36° 19°
- Mar 46° 28°
- Apr 57° 38°
- May 68° 48°
- Jun 78° 57°
- Jul 84° 63°
- Aug 82° 62°
- Sep 75° 55°
- Oct 63° 43°
- Nov 49° 33°
- Dec 38° 22°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Chicago Botanic Garden each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 16°F. The most precipitation falls in May (4.84 in), the least in February (1.98 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 32°F | 16°F | 24.3°F | 2.10 | 11.3 | 11 | <1 | 29 | 9 h 30 min |
| February | 36°F | 19°F | 27.5°F | 1.98 | 7.7 | 9 | <1 | 25 | 10 h 30 min |
| March | 46°F | 28°F | 37.0°F | 2.26 | 5.6 | 10 | <1 | 22 | 11 h 50 min |
| April | 57°F | 38°F | 47.2°F | 4.00 | 1.1 | 13 | <1 | 7 | 13 h 20 min |
| May | 68°F | 48°F | 57.9°F | 4.84 | 0.0 | 13 | 1 | <1 | 14 h 30 min |
| June | 78°F | 57°F | 67.9°F | 4.31 | 0.0 | 12 | 4 | <1 | 15 h 10 min |
| July | 84°F | 63°F | 73.4°F | 3.74 | 0.0 | 10 | 6 | <1 | 15 h |
| August | 82°F | 62°F | 72.2°F | 4.16 | 0.0 | 10 | 4 | <1 | 14 h |
| September | 75°F | 55°F | 64.9°F | 3.56 | 0.0 | 10 | 2 | <1 | 12 h 30 min |
| October | 63°F | 43°F | 52.7°F | 3.59 | 0.1 | 11 | <1 | 4 | 11 h 10 min |
| November | 49°F | 33°F | 40.8°F | 2.63 | 1.9 | 10 | <1 | 14 | 9 h 50 min |
| December | 38°F | 22°F | 29.9°F | 2.34 | 5.9 | 11 | <1 | 27 | 9 h 10 min |
| Year (annual) | 59°F | 40°F | 49.6°F | 39.51 | 33.6 | 130 | 17 | 128 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −9°C | −4.3°C | 53 mm | 29 cm |
| February | 2°C | −7°C | −2.5°C | 50 mm | 20 cm |
| March | 8°C | −2°C | 2.8°C | 57 mm | 14 cm |
| April | 14°C | 3°C | 8.4°C | 102 mm | 3 cm |
| May | 20°C | 9°C | 14.4°C | 123 mm | 0 cm |
| June | 26°C | 14°C | 19.9°C | 109 mm | 0 cm |
| July | 29°C | 17°C | 23.0°C | 95 mm | 0 cm |
| August | 28°C | 17°C | 22.3°C | 106 mm | 0 cm |
| September | 24°C | 13°C | 18.3°C | 90 mm | 0 cm |
| October | 17°C | 6°C | 11.5°C | 91 mm | 0 cm |
| November | 9°C | 0°C | 4.9°C | 67 mm | 5 cm |
| December | 3°C | −5°C | −1.2°C | 59 mm | 15 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00111497; 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.
Which months are mildest at Chicago Botanic Garden?
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 USC00111497.
When is the last frost at Chicago Botanic Garden?
In Chicago Botanic Garden, the last spring frost (32°F) comes after April 26 in half of years and after May 11 in one year in ten; the first autumn frost comes before October 21 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 261 year in 10 after May 11; 9 in 10 after April 11
- First autumn frost, half of years before
- October 211 year in 10 before October 5; 9 in 10 before November 2
NOAA puts the median frost-free season at 176 days, and the season without a hard freeze (28°F) at 202 days.
A hard freeze (28°F) comes after April 13 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Chicago Botanic Garden in zone 6a in ZIP code 60022, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 6a: the coldest night of a typical year reaches −8°F (27 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 USC00111497; 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 at Chicago Botanic Garden?
In a normal year in Chicago Botanic Garden, 17 days a year reach 90°F (1 of them 100°F or more), 128 nights fall to 32°F or colder and 130 days bring measurable precipitation.
- Days at 90°F or more
- 17a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 128a normal year
- Days that stay below freezing
- 41high of 32°F or less
- Days with 0.01 inch of precipitation
- 130a normal year
- Days with 1 inch of snow or more
- 12a normal year
The highest temperature in this station's record (since 1981) is 105°F, on July 14, 1995; the lowest is −27°F, on January 10, 1982.
The wettest calendar year on that record is 2018, with 51.09 in; the snowiest season is 2007–08, with 65.1 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00111497; records: ACIS (NOAA Regional Climate Centers), station USC00111497. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Chicago Botanic Garden?
Over a year 70% of the sunlight that would reach the ground under clear skies gets through the clouds at Chicago Botanic Garden, 3.7 kWh per square metre a day. July is the sunniest month (79%) and January the cloudiest (53%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 53% | 1.4 |
| February | 58% | 2.3 |
| March | 65% | 3.4 |
| April | 67% | 4.5 |
| May | 68% | 5.3 |
| June | 74% | 5.9 |
| July | 79% | 6.0 |
| August | 78% | 5.2 |
| September | 77% | 4.2 |
| October | 67% | 2.7 |
| November | 62% | 1.8 |
| December | 54% | 1.2 |
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 many heating and cooling degree days does Chicago Botanic Garden record?
A normal year at Chicago Botanic Garden brings 6,366 heating degree days, 18% more than the median U.S. place (5,373), and 806 cooling degree days, 11% 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 2,963 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,262 | 0 |
| February | 1,049 | 0 |
| March | 870 | 2 |
| April | 540 | 6 |
| May | 264 | 44 |
| June | 64 | 149 |
| July | 7 | 269 |
| August | 8 | 230 |
| September | 97 | 96 |
| October | 391 | 11 |
| November | 728 | 0 |
| December | 1,088 | 0 |
| Year (annual) | 6,366 | 806 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00111497. 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.
Have recent years at Chicago Botanic Garden been warmer than normal?
Over 32 complete years from 1982 to 2018, the station's annual mean temperature rose at a fitted 6.4°F per century (+0.35°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Chicago Botanic Garden's climate compare?
Chicago Botanic Garden is warmer than 28 of the 144 places with their own NOAA record in Illinois, and wetter than 65. Across the 7,247 U.S. stations with normals, its annual mean of 49.6°F is warmer than 38%.
In the Köppen classification computed from these normals, Chicago Botanic Garden 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 Chicago Botanic Garden share this climate record?
16 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.
- Evanston, ILalso near: Wheeling (12 mi, 50.8°F a year); Chicago (13 mi, 51.2°F a year)76,006 people · 8 mi SE
- Skokie, ILalso near: Wheeling (10 mi, 50.8°F a year); Chicago (10 mi, 51.2°F a year)65,850 people · 8 mi S
- Glenview, IL47,634 people · 4 mi SW
- Northbrook, IL34,546 people · 3 mi W
- Highland Park, IL30,794 people · 3 mi NW
- Wilmette, IL27,443 people · 5 mi SE
- Morton Grove, IL24,467 people · 7 mi S
- Lake Forest, IL19,642 people · 8 mi NW
- Deerfield, IL19,138 people · 4 mi NW
- Lincolnwood, IL13,055 people · 10 mi S
- Winnetka, IL12,494 people · 3 mi SE
- Glencoe, IL8,720 people · 1 mi E
- Northfield, IL5,625 people · 3 mi S
- Highwood, IL5,358 people · 5 mi N
- Kenilworth, IL2,437 people · 5 mi SE
- Golf, IL504 people · 6 mi S
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 Chicago Botanic Garden's climate
What is the coldest month at Chicago Botanic Garden?
January, with a normal high of 32°F and a normal low of 16°F. The warmest is July (84°F by day, 63°F at night).
Does it snow at Chicago Botanic Garden?
Yes: 34 inches in a normal year, falling on 23 days with 0.1 inch or more, the most in January (11.3 inches).
What is the rainiest month at Chicago Botanic Garden?
May, with 4.84 in of precipitation in a normal year; the driest is February with 1.98 in.
What plant hardiness zone is Chicago Botanic Garden in?
The USDA's 2023 map puts Chicago Botanic Garden in zone 6a in ZIP code 60022, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −8°F (27 years, 1991-2020): zone 6a.
How late can frost come at Chicago Botanic Garden?
In half of years the last 32°F night comes after April 26; in one year in ten it comes after May 11. Waiting until May 11 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Wheeling, IL6 miles from this station, 50.8°F a year
- Chicago, IL12 miles from this station, 51.2°F a year
- Waukegan, IL16 miles from this station, 48.4°F a year
- Mundelein, IL17 miles from this station, 47.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made