Frankfort Square, Illinois Weather
Fireflies rise from the lawn. Day 77 of spring. Read this microseason across nine climate regions →
Frankfort Square weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Overcast——84°50°—
- ThursdayJun 4Overcast——88°61°+4°
- FridayJun 5Heavy Drizzle66%0.04″79°70°-9°
- SaturdayJun 6Heavy Showers66%0.83″79°64°0°
- SundayJun 7Overcast24%—85°69°+6°
- MondayJun 8Showers20%—77°69°-8°
- TuesdayJun 9Light Drizzle21%—83°70°+6°
Ozone at AQI 53. AQI up 33 in the last 6 hours — air quality is degrading. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 53. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
- Present
- AQI 53
- UV peak
- 0.0 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 6
PM × Wind × Precip
PM2.5 at 6.6 µg/m³ (AQI 37) with a 0.81 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.81
- 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).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 4:25 AM
- Moonset
- 1:48 PM
- In sign
- ♑︎ Capricorn
Fireflies rise from the lawn
Frankfort Square at a glance
- Today vs. normal: 74°F — typical for the season
- Last frost: April 25 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 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 — Frankfort Square
SPC has placed Frankfort Square in the General Thunderstorms category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- DAY 3TSTMGeneral Thunderstorms
Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.
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.
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
Frankfort Square's warmest month is July (~74°F mean) and its coldest is January (~23°F). Rainfall peaks in June (4.9 inches) and bottoms out in February (2.1 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 23° | 2.5″ | 6 |
| February | 27° | 2.1″ | 5 |
| March | 37° | 2.6″ | 6 |
| April | 49° | 4.0″ | 8 |
| May | 60° | 4.6″ | 8 |
| June | 70° | 4.9″ | 7 |
| July | 74° | 4.7″ | 7 |
| August | 72° | 4.0″ | 6 |
| September | 65° | 3.4″ | 6 |
| October | 53° | 3.6″ | 7 |
| November | 40° | 3.0″ | 6 |
| December | 29° | 2.5″ | 6 |
Regional context
Frankfort Square's baseline climate, derived from NOAA NCEI 1991-2020 normals at the nearest reporting station, swings from a January mean of 23°F to a July mean of 74°F — a 51°F seasonal arc typical of the mid-latitude bands. Annual precipitation runs about 42.1 inches spread across roughly 77 days with measurable rain or snow each year.
Precipitation runs summer-dominant here: June averages 4.9 inches across 7.1 days with measurable rain, driven mostly by warm-season storms and thunderstorm activity, while February drops to just 2.1 inches across 4.7 rainy days under drier cool-season air. That summer-storm-driven distribution puts Frankfort Square in a cohort with places like Arbury Hills, IL, Frankfort, IL and Matteson, IL, all of which depend on warm-season convective activity for the bulk of their annual moisture.
The frost-sensitive growing window opens around mid-April, when overnight lows reliably clear freezing for cool-season crops like kale, peas, spinach, and parsnips. Warm-soil crops — tomatoes, peppers, eggplant — wait until soil temperatures reach the mid-50s°F, usually two weeks past the last-frost date. The window closes around mid-November, when overnight lows resume dipping below freezing and frost-tender plants need protection or harvest. These are 30-year central tendencies; year-to-year frost dates can move by up to two weeks. Local features matter: a south-facing slope inside Frankfort Square typically runs 3-5 days ahead of the regional last-frost date, while a low-lying lot along a creek or drainage can lag the same date by a week or more on calm clear nights.
Similar climates: Arbury Hills, IL, Frankfort, IL, Matteson, IL, Tinley Park, IL, Mokena, IL.
Frequently asked
- When does it freeze in Frankfort Square?
- Frankfort Square's last spring frost typically falls around mid-April, and the first fall frost arrives around mid-November.
- What is the rainy season in Frankfort Square?
- June is the wettest month with about 4.9 inches of rain on average; the city receives roughly 42 inches annually.
- What is the warmest month in Frankfort Square?
- July is typically warmest, averaging about 74°F.
- What is the coldest month in Frankfort Square?
- January is typically coldest, averaging about 23°F.
- When can I start a vegetable garden in Frankfort Square?
- Cool-season crops (peas, lettuce) can be sown around the last spring frost (mid-April); warm-season crops (tomatoes, peppers) wait until 1–2 weeks after.
- How many rainy days does Frankfort Square get?
- Frankfort Square averages about 77 rainy days per year.
- What hardiness zone is Frankfort Square?
- Frankfort Square's USDA hardiness zone is determined by its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Frankfort Square, Illinois sits in a warm-summer humid continental climate zone. January means hover near 23°F while July averages 74°F — a 51°F seasonal swing.
Across the year, Frankfort Square receives about 42 inches of precipitation spread over roughly 77 rainy days.
The rhythm of the year is set by latitude (41.5°N), proximity to large water bodies, and elevation — all of which shape what grows here, when frost is likely, and what the weather story looks like day to day.