September
September · June · August
United States · 1991–2020
September leads for comfortable weather in Golden: typically 24.6°C by day, 10.7°C at night, with 47 mm of rain. Based on measured 1991–2020 NOAA station history.
September · June · August
August · July · June
May · September · October
The weakest month is December, scoring 6 against September’s 87 — days reach only 6.8°C, 17° below the 24°C the score treats as ideal, and nights drop to -5.5°C.
Month by month
The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.
| Month | Day | Night | Rain | Wet days | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|
| January | 7.6°C | -4.9°C | 18 mm | 3.3 | 9 h 38 | 10 | Good coverage |
| February | 7.2°C | -5.6°C | 22 mm | 3.8 | 10 h 38 | 7 | Good coverage |
| March | 12°C | -1.5°C | 42 mm | 5.1 | 11 h 49 | 28 | Good coverage |
| April | 15.3°C | 1.7°C | 66 mm | 6.7 | 13 h 12 | 40 | Good coverage |
| May | 20.1°C | 6.8°C | 71 mm | 7.4 | 14 h 21 | 64 | Good coverage |
| June | 27.2°C | 12.5°C | 43 mm | 6 | 14 h 58 | 81 | Good coverage |
| July | 30.7°C | 16.1°C | 45 mm | 6.3 | 14 h 43 | 71 | Good coverage |
| August | 29°C | 14.8°C | 49 mm | 6.5 | 13 h 44 | 78 | Good coverage |
| September | 24.6°C | 10.7°C | 47 mm | 5.1 | 12 h 24 | 87 | Good coverage |
| October | 17.2°C | 4°C | 34 mm | 4.6 | 11 h 05 | 56 | Good coverage |
| November | 11.8°C | -1.1°C | 24 mm | 3.9 | 9 h 56 | 30 | Good coverage |
| December | 6.8°C | -5.5°C | 18 mm | 3.4 | 9 h 22 | 6 | Good coverage |
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 21.7°C21 Jan 2005 | -25.6°C16 Jan 2024 | 22 mm26 Jan 1998 | 48 mm2019 · driest 1 mm in 2020 | 29 |
| February | 23.3°C11 Feb 2017 | -27.2°C3 Feb 2011 | 47 mm3 Feb 2012 | 71 mm2012 · driest 1 mm in 2026 | 29 |
| March | 31.1°C22 Mar 2026 | -21.1°C4 Mar 2019 | 45 mm19 Mar 2003 | 113 mm2003 · driest 0 mm in 2012 | 29 |
| April | 28.9°C13 Apr 2025 | -16.7°C10 Apr 2013 | 51 mm18 Apr 2009 | 144 mm1999 · driest 1 mm in 2002 | 30 |
| May | 34.4°C30 May 2000 | -7.8°C7 May 1978 | 60 mm12 May 2023 | 170 mm2015 · driest 12 mm in 2006 | 30 |
| June | 38.9°C26 Jun 2012 | 0.0°C6 Jun 1998 | 43 mm5 Jun 2015 | 122 mm2015 · driest 5 mm in 2012 | 31 |
| July | 38.3°C17 Jul 2003 | 8.3°C31 Jul 2009 | 95 mm17 Jul 2000 | 125 mm2014 · driest 3 mm in 2008 | 31 |
| August | 37.2°C17 Aug 2002 | 5.6°C2 Aug 1978 | 54 mm5 Aug 1999 | 124 mm1999 · driest 6 mm in 2012 | 29 |
| September | 36.7°C3 Sep 2019 | -2.2°C29 Sep 1999 | 267 mm13 Sep 2013 | 410 mm2013 · driest 1 mm in 2010 | 30 |
| October | 30.6°C3 Oct 2024 | -17.2°C30 Oct 2019 | 37 mm10 Oct 2005 | 90 mm2009 · driest 2 mm in 2021 | 29 |
| November | 26.1°C3 Nov 2025 | -22.8°C14 Nov 2014 | 25 mm26 Nov 2019 | 54 mm2015 · driest 0 mm in 2025 | 28 |
| December | 22.2°C23 Dec 2025 | -26.1°C22 Dec 2022 | 40 mm29 Dec 2022 | 78 mm2006 · driest 0 mm in 2002 | 29 |
| Month | Days 25°C+ | Days 30°C+ | Frost nights | Heavy rain (10 mm+) | Snow days |
|---|---|---|---|---|---|
| January | 0 | 0 | 25 | <1 | 4 |
| February | 0 | 0 | 23 | <1 | 4 |
| March | <1 | 0 | 19 | 1 | 4 |
| April | 2 | 0 | 11 | 2 | 3 |
| May | 9 | 1 | 3 | 2 | 1 |
| June | 21 | 11 | 0 | 1 | 0 |
| July | 29 | 20 | 0 | 1 | 0 |
| August | 26 | 15 | 0 | 1 | 0 |
| September | 18 | 5 | <1 | 1 | <1 |
| October | 4 | 0 | 7 | 2 | 2 |
| November | <1 | 0 | 18 | <1 | 3 |
| December | 0 | 0 | 25 | <1 | 4 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | <1% | 11% | 1% | 7% | 4.1–9.3°C |
| February | 2% | 14% | 2% | 7% | 4.6–10.9°C |
| March | 13% | 18% | 5% | 16% | 9.7–15.3°C |
| April | 28% | 21% | 6% | 21% | 12.5–18.3°C |
| May | 51% | 27% | 8% | 31% | 16.9–22.6°C |
| June | 78% | 21% | 5% | 20% | 24.1–29.5°C |
| July | 81% | 22% | 4% | 25% | 29.2–32.2°C |
| August | 79% | 21% | 4% | 20% | 27.4–31.3°C |
| September | 76% | 17% | 4% | 14% | 22.7–27.7°C |
| October | 42% | 14% | 3% | 9% | 14.8–19.8°C |
| November | 12% | 13% | 3% | 8% | 9.1–15.0°C |
| December | 1% | 11% | 2% | 6% | 5.0–10.3°C |
A warm and dry day reaches 20°C with under 1 mm of rain; a wet day gets 1 mm or more; a washout gets 10 mm or more. The week column is the share of seven-day stretches in that month, across the station’s whole daily record, that contained three or more wet days — the odds a week-long trip is rained on repeatedly, counted rather than modelled. The last column is the 10th to 90th percentile of that month’s daytime average across individual years: a narrow band means the average is what you will get, a wide one means the average is a midpoint between years that felt quite different.
The evidence behind this page