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Denver, Colorado Weather in September

Typical September in Denver, Colorado: days around 80°F, nights around 50°F, and the month cools about 8°F from early to late — based on 30-year climate normals (NOAA, 1991–2020), day by day below.

80°Faverage high

50°Faverage low

−8°Fearly vs late September

30°Fday-to-night swing

Traveling soon? See the live 16-day Denver forecast →

Early, mid and late September in Denver

The month split in three — the part of the answer a 30-row table hides.

Part of September	Avg high	Avg low
Early September (Sep 1–10)	83°F	54°F
Mid September (Sep 11–20)	80°F	50°F
Late September (Sep 21–30)	75°F	46°F

Daylight in Denver during September

How much light the day gives you — useful for planning what you can still do after work.

13 h 03 minon Sep 1

11 h 49 minon Sep 30

−1 h 14 minlost across September

Day-by-day September normals for Denver

Long-term daily averages (NOAA 1991–2020) — climate, not a live forecast. For the next 16 days, use the live forecast.

Day	Avg high	Avg low
Sep 1	85°F	55°F
Sep 2	84°F	55°F
Sep 3	84°F	54°F
Sep 4	84°F	54°F
Sep 5	84°F	54°F
Sep 6	83°F	54°F
Sep 7	83°F	53°F
Sep 8	83°F	53°F
Sep 9	82°F	53°F
Sep 10	82°F	52°F
Sep 11	82°F	52°F
Sep 12	81°F	52°F
Sep 13	81°F	51°F
Sep 14	81°F	51°F
Sep 15	80°F	50°F
Sep 16	80°F	50°F
Sep 17	79°F	50°F
Sep 18	79°F	49°F
Sep 19	78°F	49°F
Sep 20	78°F	48°F
Sep 21	78°F	48°F
Sep 22	77°F	48°F
Sep 23	77°F	47°F
Sep 24	76°F	47°F
Sep 25	76°F	46°F
Sep 26	75°F	46°F
Sep 27	74°F	45°F
Sep 28	74°F	45°F
Sep 29	74°F	44°F
Sep 30	73°F	44°F

September in Denver through the years

Real photos taken in Denver in September by Weathershot app users — different years, same month.

Clear weather in Denver, 86°F — September 27, 2021 (community photo) — ☀️ Clear · 86°F · Sep 2021📷 Gary W.

Weather in Denver — September 10, 2022 (community photo) — 📷 Sep 2022📷 Kim G.

Cloudy weather in Denver, 72°F — September 14, 2022 (community photo) — ☁️ Cloudy · 72°F · Sep 2022📷 Barbara S. B.

Weather in Denver, 66°F — September 10, 2023 (community photo) — 📷 66°F · Sep 2023📷 AZD5280

Weather in Denver, 88°F — September 22, 2024 (community photo) — 📷 88°F · Sep 2024📷 AZD5280

Clear weather in Denver, 84°F — September 25, 2024 (community photo) — ☀️ Clear · 84°F · Sep 2024📷 Sarah P.

Weather in Denver, 68°F — September 7, 2025 (community photo) — 📷 68°F · Sep 2025📷 Freddie L.

More months: October · November · December · January · Live Denver forecast

September elsewhere: Atlanta weather in September · Chicago weather in September · Miami weather in September · New York weather in September · Phoenix weather in September · Seattle weather in September

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The September photos above were taken with Weathershot — it stamps the real weather onto your picture. Snap one in Denver and it could land on this page.

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