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

Thomson Illinois Climate Data

Monthly Average Climate Data for Thomson Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January12.7 °F29.3 °F1.55 in.
February16.4 °F33.9 °F1.72 in.
March27.4 °F46.4 °F2.43 in.
April38.1 °F59.8 °F3.62 in.
May49.9 °F71.4 °F4.48 in.
June59.9 °F80.8 °F5.13 in.
July63.3 °F84.0 °F4.19 in.
August61.1 °F82.1 °F3.87 in.
September52.6 °F75.9 °F3.65 in.
October41.1 °F62.8 °F2.75 in.
November29.7 °F47.6 °F2.27 in.
December19.4 °F34.8 °F1.9 in.
Annual39.3 °F59.1 °F37.56 in.

Climate Data for Thomson Illinois

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateApr. 11 - Apr. 20
Average Days With Frost100-125 Days
Plant Hardiness ZoneZone 5b : -15°F to -10°F
Plant Hardiness Zone - 2012Zone 5b : -15°F to -10°F
Current Drought ConditionsAbnormally Dry
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
2026 plantmaps.com