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

Olney Illinois Climate Data

Monthly Average Climate Data for Olney Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January22.4 °F38.4 °F3.42 in.
February25.3 °F43.4 °F2.54 in.
March33.9 °F53.9 °F3.98 in.
April44.2 °F66.0 °F4.95 in.
May55.1 °F75.7 °F5.28 in.
June63.9 °F84.4 °F4.9 in.
July66.7 °F87.3 °F4.6 in.
August64.3 °F86.4 °F2.81 in.
September56.6 °F81.2 °F3.32 in.
October45.1 °F69.1 °F3.66 in.
November34.8 °F54.5 °F4.04 in.
December26.9 °F42.9 °F3.4 in.
Annual44.9 °F65.3 °F46.9 in.

Climate Data for Olney Illinois

Average First Frost DateOct. 11 - Oct. 20
Average Last Frost DateApr. 1 - Apr. 10
Average Days With Frost75-100 Days
Plant Hardiness ZoneZone 6b : -5°F to 0°F
Plant Hardiness Zone - 2012Zone 6a : -10°F to -5°F
Current Drought ConditionsSevere Drought
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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