NOAA GHCND · LIVE

Weather on December 21

Naperville, IL

55 Years of Data

Avg High
35°F
Avg Low
18°F
Warmest
2006
44°F avg
Coldest
1989
-6°F avg

About This Date

December 21st in Naperville, IL typically brings cold winter weather, with average highs around 35°F and lows near 18°F. Over 55 years of records, the warmest December 21st was in 2006 (44°F average), while the coldest was 1989 (-6°F) — a 50°F range across recorded history. Precipitation has occurred on 29% of recorded December 21st dates, with snow falling 20% of the time (heaviest snowfall: 5.5"). The last decade has been 4.6°F warmer on this date compared to 20-30 years ago.

The last decade has been 4.6°F warmer on this date compared to 20-30 years ago.

Planning for December 21st in Naperville, IL? Bundle up with warm layers and protect extremities from the cold. Check road conditions if traveling, as snow is possible.

Warming Trend
1.5°F per decade on this date
YearHighLowAvgPrecipSnow
202539°14°27°
202430°14°22°
202342°25°33°
202231°10°20°
202142°20°31°
202041°31°36°
201940°17°28°
201846°33°40°0.25"
201737°27°32°
201629°17°23°
201551°32°42°1.7"
201433°28°31°
201334°29°31°
201249°26°37°1.07"0.2"
201139°36°37°0.03"
201029°10°19°0.64"3.4"
200930°25°27°0.2"
200831°-7°12°0.25"0.5"
200740°27°33°0.38"
2006warmest51°37°44°1.02"
200522°13°
200433°25°29°
200347°23°35°
200236°29°32°0.05"
200145°19°32°
200020°11°0.41"3"
199918°
199837°19°28°
199739°25°32°
199637°13°25°
199533°11°22°
199448°24°36°
199333°24°29°
199232°15°24°
199134°27°30°
199036°28°32°
1989coldest-15°-6°0.15"0.3"
198839°28°34°
198740°23°31°
198643°22°32°
198520°-3°
198452°25°38°
198325°15°20°0.46"2"
198235°14°25°
198133°12°23°0.58"2.4"
198022°11°
197944°25°34°
197830°13°21°0.79"
197731°17°24°1.98"5.5"
197617°0.2"
197534°12°23°
197434°28°31°0.51"2.5"
197324°-1°12°
197235°32°34°
197137°25°31°
55 years of data from WHEATON 3 SE

Naperville, IL Temperature Range by Month

Average monthly highs and lows. The shaded band shows the typical daily temperature range.

0°20°40°60°80°JFMAMJJASOND
Avg high Avg low

Naperville, IL Monthly Precipitation

Average rainfall and snowfall per month, in inches.

0"5.8"11.5"JFMAMJJASOND2.0"0"
Rain (in) Snow (in)

Naperville, IL Daily Temperature Calendar

Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.

151015202531JanFebMarAprMayJunJulAugSepOctNovDec
Cooler
Hotter
20°40°60°80°100°

Best Time to Visit Naperville, IL

Naperville, IL has no months that meet our "pleasant" threshold — every season has tradeoffs.

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Pleasant (65-82°F, ≤2.5" rain) Mild Less ideal

Browse Weather History

Weather data provided by NOAA Climate Data Online. Not for critical planning.

📬 Free weekly newsletter

This week in weather history.

Five notable weather anniversaries from the week ahead — deadliest tornadoes, record temps, historic storms — every Sunday. No spam, unsubscribe anytime.

4,200+ readers · Sunday delivery