NOAA GHCND · LIVE

Weather on September 18

Denver, CO

55 Years of Data

Avg High
80°F
Avg Low
46°F
Warmest
2018
74°F avg
Coldest
1971
31°F avg

About This Date

September 18th in Denver, CO typically brings warm fall weather, with average highs around 80°F and lows near 46°F — a 34°F daily swing. Over 55 years of records, the warmest September 18th was in 2018 (74°F average), while the coldest was 1971 (31°F) — a 43°F range across recorded history. Precipitation has occurred on 22% of recorded September 18th dates, with snow falling 2% of the time. Temperatures on this date have remained relatively stable over the past several decades.

Temperatures on this date have remained relatively stable over the past several decades.

Planning for September 18th in Denver, CO? Stay hydrated and seek shade during peak afternoon hours.

Warming Trend
1.3°F per decade on this date
YearHighLowAvgPrecipSnow
202575°44°60°0.05"
202484°44°64°
202386°41°64°
202285°50°67°
202173°44°59°
202085°48°66°
201989°55°72°
2018warmest93°55°74°
201771°49°60°0.03"
201682°48°65°
201576°49°62°
201490°52°71°
201384°52°68°
201266°43°54°
201178°44°61°
201086°52°69°0.1"
200978°46°62°
200888°52°70°
200773°54°63°0.18"
200667°38°52°
200589°45°67°
200493°52°72°
200386°35°61°0.13"
200285°49°67°
200175°44°60°
200085°59°72°
199982°46°64°
199892°52°72°
199783°56°69°
199662°38°50°1.8"
199586°45°65°
199485°48°66°
199371°41°56°0.46"
199270°41°55°
199155°39°47°0.1"
199076°50°63°1.17"
198988°58°73°
198881°
198767°38°52°
198672°44°58°
198583°58°70°
198484°50°67°
198384°43°63°
198276°44°60°0.08"
198187°40°63°
198090°46°68°
197979°44°61°
197874°48°61°
197778°36°57°
197681°48°64°0.08"
197578°39°59°
197480°40°60°
197384°39°62°
197285°52°68°
1971coldest40°23°31°0.2"0.9"
55 years of data from NORTHGLENN

Denver, CO Temperature Range by Month

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

10°30°50°70°90°JFMAMJJASOND
Avg high Avg low

Denver, CO Monthly Precipitation

Average rainfall and snowfall per month, in inches.

0"3.1"6.2"JFMAMJJASOND2.1"0"
Rain (in) Snow (in)

Denver, CO 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 Denver, CO

Denver, CO 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