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

Royal Illinois Climate Data

Monthly Average Climate Data for Royal Illinois

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January17.8 °F33.6 °F2.35 in.
February21.0 °F38.2 °F2.09 in.
March30.1 °F49.8 °F2.81 in.
April40.7 °F63.5 °F4.03 in.
May52.5 °F73.7 °F4.51 in.
June61.5 °F82.0 °F4.76 in.
July64.2 °F84.3 °F4.2 in.
August61.9 °F82.9 °F3.26 in.
September54.6 °F78.3 °F3.27 in.
October43.0 °F65.7 °F3.38 in.
November32.4 °F51.1 °F3.19 in.
December23.5 °F38.5 °F2.4 in.
Annual41.9 °F61.8 °F40.25 in.

Climate Data for Royal 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 ConditionsExtreme Drought
Köppen Climate ClassificationDfa - Humid Continental Hot Summers With Year Around Precipitation
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