select pnm,lnm,st_cd,st_nm,cnty_id,dm,dm_date,dm_hist,avg_tmax_data,avg_tmin_data,avg_prcp_data,rec_hi_data,rec_lo_data,avg_sndp_data,x,y,ff,lf,fd,hz,er,hz_source,kg,hzd,clim_stn_nm,hz12,hz90, feels_like_min,feels_like_max,days_of_prcp,snow,cloud_cover,humidity,wind_speed from worldtg8_pm.pm_climate_points_namer where surl = 'mount-prospect' and st_surl='illinois' and iso_cc = 'US' and prim_loc in (1,2) Mount Prospect Illinois Climate Data - Updated February 2026

Mount Prospect Illinois Climate Data

Monthly Average Climate Data for Mount Prospect Illinois

Switch Data to Celsius/Metric Units

Month	Avg. Low	Avg. High	Avg. Precip
January	16.4 °F	31.3 °F	2.04 in.
February	19.1 °F	35.1 °F	1.93 in.
March	28.3 °F	45.9 °F	2.27 in.
April	38.5 °F	57.9 °F	3.75 in.
May	49.4 °F	69.2 °F	4.58 in.
June	59.3 °F	79.4 °F	4.4 in.
July	64.7 °F	83.7 °F	3.63 in.
August	63.3 °F	81.8 °F	4.02 in.
September	55.3 °F	75.2 °F	3.29 in.
October	43.4 °F	62.5 °F	3.21 in.
November	32.2 °F	48.3 °F	2.46 in.
December	22.3 °F	36.6 °F	2.16 in.
Annual	41 °F	58.9 °F	37.74 in.

Climate Data for Mount Prospect Illinois

Average First Frost Date	Oct. 21 - Oct. 31
Average Last Frost Date	Apr. 21 - Apr. 30
Average Days With Frost	75-100 Days
Plant Hardiness Zone	Zone 6a : -10°F to -5°F
Plant Hardiness Zone - 2012	Zone 5b : -15°F to -10°F
Current Drought Conditions	Normal
Köppen Climate Classification	Dfa - Humid Continental Hot Summers With Year Around Precipitation

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