Summit, Illinois Weather
Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Summit weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Thunderstorm80%0.86″83°68°—
- SundayJul 5Overcast12%—75°66°-8°
- MondayJul 6Overcast——82°67°+7°
- TuesdayJul 7Overcast——85°65°+3°
- WednesdayJul 8Overcast22%—86°66°+1°
- ThursdayJul 9Light Showers36%0.22″81°68°-5°
- FridayJul 10Overcast36%—82°67°+1°
AQI 38 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 6.4 µg/m³ (AQI 36) with a 0.94 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 6.4 µg/m³ (AQI 36) with a 0.94 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.94
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).








































If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 10:49 PM
- Moonset
- 9:55 AM
- In sign
- ♓︎ Pisces
Cicadas claim the afternoon
Summit at a glance
- Today vs. normal: 4°F above the seasonal normal for this latitude
- Last frost: April 27 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
16-Day Forecast — Summit
- Sat83°69°80%
- Sun75°66°12%
- Mon82°67°8%
- Tue85°65°2%
- Wed86°66°22%
- Thu81°68°36%
- Fri82°67°36%
- Sat86°66°19%
- Sun73°64°9%
- Mon78°62°10%
- Tue80°64°8%
- Wed86°66°23%
- Thu89°69°16%
- Fri88°73°19%
- Sat91°72°19%
- Sun91°73°28%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Peak growing season
As of July 4, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
SPC Convective Outlook
Storm Prediction Center — Summit
SPC has placed Summit in the Marginal Risk category for severe thunderstorms today.
- TODAYMRGLMarginal Risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3NONENo severe risk
Isolated severe storms possible. Limited threat for hail or damaging wind.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.
Microseason · July 1–5
Cicadas claim the afternoon
Annual cicada buzz begins, peaking in the heat of the day.
Day 185 of 365 · Wedge 37 of 72
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | lettuce, peas, spinach, radishes | — |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
Summit's warmest month is July (~76°F mean) and its coldest is January (~24°F). Rainfall peaks in May (4.2 inches) and bottoms out in January (2.0 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 24° | 2.0″ | 16 |
| February | 27° | 2.1″ | 14 |
| March | 37° | 3.0″ | 16 |
| April | 50° | 3.8″ | 17 |
| May | 59° | 4.2″ | 18 |
| June | 70° | 4.0″ | 17 |
| July | 76° | 2.9″ | 15 |
| August | 75° | 3.0″ | 14 |
| September | 68° | 3.1″ | 14 |
| October | 55° | 3.0″ | 13 |
| November | 40° | 3.2″ | 16 |
| December | 28° | 2.5″ | 15 |
Regional context
Summit's climate, from NOAA NCEI 1991-2020 station normals, pairs 24°F Januarys with 76°F Julys — a 53°F swing. About 36.8 inches of precipitation falls over roughly 184 days a year.
Summit's precipitation spreads evenly: May peaks at 4.2 inches on 18.2 wet days, while January holds 2.0 inches over 15.7 — no month dominates Summit's rain calendar. That even rhythm groups Summit with places like McCook, IL, Lyons, IL and Bedford Park, IL.
By mid-April the frosts ease in Summit, opening the season for kale, peas, spinach, and parsnips. Warm-soil crops in Summit wait about two weeks past Summit's last frost, once the soil warms. It shuts near mid-November, when freezes return to Summit and tender plants need cover. Within Summit, cold-air pooling chills low spots by 5-10°F, shifting Summit's local frost dates.
Similar climates: McCook, IL, Lyons, IL, Bedford Park, IL, Forest View, IL, Justice, IL.
Frequently asked
- When does it freeze in Summit?
- Frost typically leaves Summit by mid-April and returns to Summit near mid-November.
- What is the rainy season in Summit?
- Rainfall in Summit peaks in May near 4.2 inches, out of about 37 inches annually.
- What is the warmest month in Summit?
- July is Summit's warmest month, averaging about 76°F.
- What is the coldest month in Summit?
- Summit bottoms out in January, with a mean near 24°F.
- When can I start a vegetable garden in Summit?
- Frost-hardy sowings begin at mid-April in Summit; warm-season starts follow two weeks on.
- How many rainy days does Summit get?
- Summit records around 184 days of measurable precipitation annually.
- What hardiness zone is Summit?
- Summit sits in the USDA zone set by January lows near 24°F; the USDA ZIP tool gives the band.
- What is the 10-day forecast for Summit?
- Summit's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Summit?
- See this week's day-by-day rain chances for Summit in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Summit?
- Current conditions for Summit and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Summit forecast updated?
- The Summit forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Summit?
- Today's sunrise and sunset times for Summit are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Summit?
- The next few days in Summit's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
Summit, Illinois occupies a warm-summer humid continental zone, with January means near 24°F and July around 76°F — a 52°F swing.
Yearly precipitation in Summit totals around 37 inches, spread over about 184 days of rain or snow.
The 52°F gap between Summit's summer and winter, at 41.8°N, shapes Summit's frost calendar.
ZIP codes in Summit
- 60501