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 = 'forsyth' and st_surl='illinois' and iso_cc = 'US' and prim_loc in (1,2) Forsyth Illinois Climate Data - Updated February 2026

Forsyth Illinois Climate Data

Monthly Average Climate Data for Forsyth Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January18.6 °F34.8 °F2.29 in.
February21.1 °F39.6 °F2.03 in.
March30.4 °F50.8 °F2.74 in.
April41.6 °F64.3 °F4.12 in.
May53.1 °F74.2 °F4.57 in.
June61.6 °F83.3 °F4.64 in.
July64.7 °F86.0 °F3.82 in.
August62.9 °F84.2 °F3.28 in.
September54.5 °F79.3 °F3.13 in.
October42.7 °F66.6 °F3.31 in.
November32.1 °F51.7 °F3.06 in.
December24.2 °F39.6 °F2.4 in.
Annual42.3 °F62.9 °F39.39 in.

Climate Data for Forsyth Illinois

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateApr. 11 - Apr. 20
Average Days With Frost75-100 Days
Plant Hardiness ZoneZone 6a : -10°F to -5°F
Plant Hardiness Zone - 2012Zone 5b : -15°F to -10°F
Current Drought ConditionsSevere Drought
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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