Climate reading

Denver and the Chinese solar calendar

In Denver, the first freeze typically comes October 6, 17 days before the calendar's Frost's Descent begins on October 23. The last freeze is typically over by May 6, and Denver gets 151 days a year without one. Where the calendar and your weather disagree, go by your weather.

The weather station behind this page

Weather station	Denver Intl, CO
Station ID	USW00003017
Days without a freeze, per year	151
Typical first freeze	October 6
Typical last freeze	May 6
Rain and heat	r = 0.65 (move together)
Years averaged	1991–2020

Official NOAA averages for 1991–2020 at this station: a typical year, not a forecast.

Rain and heat across the whole year

Here the rainy weeks tend to be the warm weeks, as they are where the calendar comes from, so on rain the calendar fits Denver. On a scale from −1 (opposite) to 1 (perfectly together), Denver scores 0.65 and the calendar's home region 0.88.

Where the calendar is most wrong about Denver

These four two-week stretches are where the calendar's names or advice sit furthest from Denver's thirty-year record.

Cold Dew 寒露from 2026-10-08

The old calendar's three signs for these weeks, one per five days: 鸿雁来宾 · 雀入大水为蛤 · 菊有黄华

The Su Wen, part of the Yellow Emperor's Inner Classic, calls fall the season of containment and levelling (容平). Go to bed early and get up early, it says, up with the rooster. That keeps you in step with fall. Go against it, the text warns, and the lungs suffer, showing up in winter as diarrhea with undigested food.

Average, low, high	51.4°F / 37.2°F / 65.5°F
Days with measurable rain	17.0%
Days at or below freezing	4.5
Daylight	11h 23m (-40 min from two weeks ago)

Where the calendar comes from, these weeks average about 59.0°F. At Denver Intl, CO: 51.4°F, 7.6°F cooler.
'Cold Dew' names what people in the Yellow River valley saw in nature, not a temperature. At Denver Intl, CO, half of all years have had their first freeze by October 6, 2 days before these weeks begin; they usually bring about 4.5 freezing days.
The fastest-cooling stretch of the year: 7.1°F cooler than the two weeks before.

Minor Snow 小雪from 2026-11-22

The old calendar's three signs for these weeks, one per five days: 虹藏不见 · 天气上升地气下降 · 闭塞而成冬

The Su Wen calls winter the season of closing and storing (閉藏). Go to bed early and get up late, once the sun is up; stay warm without sweating. That keeps you in step with winter. Go against it, the text warns, and the kidneys suffer, showing up in spring as weakness and collapse (痿厥).

Average, low, high	34.4°F / 21.4°F / 47.4°F
Days with measurable rain	15.4%
Days at or below freezing	12.5
Daylight	9h 44m (-27 min from two weeks ago)

Where the calendar comes from, these weeks average about 40.6°F. At Denver Intl, CO: 34.4°F, 6.2°F cooler.
'Minor Snow' names what people in the Yellow River valley saw in nature, not a temperature. At Denver Intl, CO, half of all years have had their first freeze by October 6, 47 days before these weeks begin; they usually bring about 12.5 freezing days.

Yang deficiency (running low on the body's warmth) traditionally finds winter hard. Here the average low this stretch is 21.4°F.

Major Snow 大雪from 2026-12-07

The old calendar's three signs for these weeks, one per five days: 鹖鴠不鸣 · 虎始交 · 荔挺出

The winter advice above covers these weeks too.

Average, low, high	30.9°F / 18.2°F / 43.7°F
Days with measurable rain	14.8%
Days at or below freezing	14.1
Daylight	9h 26m (-18 min from two weeks ago)

Where the calendar comes from, these weeks average about 36.3°F. At Denver Intl, CO: 30.9°F, 5.4°F cooler.
'Major Snow' names what people in the Yellow River valley saw in nature, not a temperature. At Denver Intl, CO, half of all years have had their first freeze by October 6, 62 days before these weeks begin; they usually bring about 14.1 freezing days.

Blood stasis (blood that doesn't move freely) traditionally finds cold hard. Here the average low this stretch is 18.2°F.

Frost's Descent 霜降from 2026-10-23

The old calendar's three signs for these weeks, one per five days: 豺祭兽 · 草木黄落 · 蛰虫咸俯

The fall advice above covers these weeks too.

Average, low, high	45.5°F / 31.6°F / 59.5°F
Days with measurable rain	16.6%
Days at or below freezing	7.2
Daylight	10h 45m (-38 min from two weeks ago)

Where the calendar comes from, these weeks average about 53.4°F. At Denver Intl, CO: 45.5°F, 7.9°F cooler.
'Frost's Descent' names what people in the Yellow River valley saw in nature, not a temperature. At Denver Intl, CO, half of all years have had their first freeze by October 6, 17 days before these weeks begin; they usually bring about 7.2 freezing days.

All twenty-four two-week stretches in Denver

Two weeks		Begins	Avg °F	Rainy days %	Freezing days	vs. calendar °F
Minor Cold	小寒	2026-01-05	31.8	13.8	14.0	-1.3
Major Cold	大寒	2026-01-20	31.6	15.6	13.9	-2.4
Start of Spring	立春	2026-02-04	31.7	18.0	12.6	-6.6
Rain Water	雨水	2026-02-18	35.1	19.2	13.8	-7.7
Awakening of Insects	惊蛰	2026-03-05	40.6	20.1	11.2	-7.4
Spring Equinox	春分	2026-03-20	44.8	23.6	10.7	-9.0
Pure Brightness	清明	2026-04-05	47.0	28.3	6.6	-11.8
Grain Rain	谷雨	2026-04-20	50.3	31.1	5.2	-14.3
Start of Summer	立夏	2026-05-05	56.0	32.6	1.5	-11.6
Grain Buds	小满	2026-05-21	62.1	32.1	1.0	-10.2
Grain in Ear	芒种	2026-06-05	67.3	29.0	0.0	-9.2
Summer Solstice	夏至	2026-06-21	72.1	25.9	0.0	-6.9
Minor Heat	小暑	2026-07-07	75.3	26.1	0.0	-4.8
Major Heat	大暑	2026-07-23	75.4	27.5	0.0	-5.9
Start of Autumn	立秋	2026-08-07	73.2	25.0	0.0	-5.1
End of Heat	处暑	2026-08-23	70.2	21.3	0.1	-4.6
White Dew	白露	2026-09-07	65.5	19.8	0.4	-3.0
Autumn Equinox	秋分	2026-09-23	58.5	18.2	2.3	-5.4
Cold Dew	寒露	2026-10-08	51.4	17.0	4.5	-7.6
Frost's Descent	霜降	2026-10-23	45.5	16.6	7.2	-7.9
Start of Winter	立冬	2026-11-07	40.0	15.8	11.3	-6.6
Minor Snow	小雪	2026-11-22	34.4	15.4	12.5	-6.2
Major Snow	大雪	2026-12-07	30.9	14.8	14.1	-5.4
Winter Solstice	冬至	2026-12-22	30.8	13.8	13.2	-3.0

‘vs. calendar’ is how much warmer (+) or cooler (−) each stretch runs here than where the calendar comes from. Rain figures count rainy days, not inches.

The body-type notes follow traditional Chinese medicine as set out in a national standard in China. Tying them to this city's weather is a traditional association, not a finding from modern research. Which type goes with which stretch is our own arrangement: each is matched to the time of year the standard says it finds hard, or, for rain, to the rainiest of the four when it's wetter than Denver's year as a whole. Weather doesn't decide anyone's body type. To find yours, take the assessment.

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How Denver compares with the other thirteen

Denver has 151 frost-free days a year, the fewest of the fourteen. It's 214 fewer than San Francisco, which has the most.

Rain falls on 21.7% of days here over a year. Phoenix is the driest of the fourteen at 9.2% and Seattle the wettest at 43.1%, which puts Denver at the dry end.

The hottest two weeks here are Minor Heat, with an average high of 90.2°F and rain on 26.1% of days: hot, with rain about one day in four. 4 of the fourteen get hotter at their peak, Phoenix among them.

The other thirteen cities

All fourteen cities side by side

Where this comes from

The thirty-year averages are NOAA's official 1991–2020 figures, one station per city, read straight from NOAA's records by our own program. Freezing days for each two-week stretch are estimated from NOAA's monthly counts. Figures for where the calendar comes from are based on weather-station measurements and reanalysis data from the Yellow River valley in northern China, where the calendar's names come from. The seasonal advice comes from the Su Wen, in our own translation.