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Tucson, Arizona climate

BSh Hot semi-arid

Tucson has a seasonal warm-temperate climate (Hot semi-arid, Köppen BSh). The hottest month is July with an average daily high near 100°F, while the coldest is December averaging around 42°F at night. Precipitation totals about 12 inches a year and is strongly seasonal — August alone averages 2.6 inches while May barely receives 0.17 inches.

☀️ Summers

Very hot

Highs near 100°F in July.

About 143 days a year above 90 °F

❄️ Winters

Cool

Lows near 42°F in December.

About 5 freezing nights a year

🌧️ Rain

Fairly dry

About 12 in of rain a year.

Wettest in August

⛅ Sky & trend

Fairly sunny

More sun than cloud through the year.

+0.3 °F vs 50 years ago

Temperature & precipitation

Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figures

Clear vs cloudy days

Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day counts

Tucson climate normals (1991–2020)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°F)	66	69	76	83	91	101	100	98	95	86	75	65
Avg temp (°F)	54	57	63	69	78	87	88	87	83	73	62	53
Avg low (°F)	42	45	50	56	64	73	77	76	72	60	50	42
Precipitation (in)	0.9	0.8	0.6	0.3	0.2	0.3	2.1	2.6	1.7	0.6	0.6	0.9

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Avg high (°F)	66	69	76	83	91	101
Avg temp (°F)	54	57	63	69	78	87
Avg low (°F)	42	45	50	56	64	73
Precipitation (in)	0.9	0.8	0.6	0.3	0.2	0.3

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°F)	100	98	95	86	75	65
Avg temp (°F)	88	87	83	73	62	53
Avg low (°F)	77	76	72	60	50	42
Precipitation (in)	2.1	2.6	1.7	0.6	0.6	0.9

How often — frequency of weather events

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	4	4	4	1	1	2	8	9	3	3	2	4
Days with high ≥ 90°F (days)	—	—	0.6	6	21	27	28	27	23	11	0.2	—
Days with low ≤ 32°F (days)	2	0.5	0.1	—	—	—	—	—	—	—	0.2	2

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Days with measurable rain (days)	4	4	4	1	1	2
Days with high ≥ 90°F (days)	—	—	0.6	6	21	27
Days with low ≤ 32°F (days)	2	0.5	0.1	—	—	—

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	8	9	3	3	2	4
Days with high ≥ 90°F (days)	28	27	23	11	0.2	—
Days with low ≤ 32°F (days)	—	—	—	—	0.2	2

Sky & atmosphere

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	39	43	37	27	25	23	55	52	33	26	31	38
Clear days (≤ 30% cloud)	15	13	16	19	21	21	7	8	17	21	18	14
Partly cloudy days (30–70%)	8	8	9	8	7	6	12	14	9	6	7	10
Cloudy days (≥ 70%)	7	8	7	3	3	3	11	10	5	4	5	7
Relative humidity (%)	48	46	39	30	24	20	41	47	43	38	39	47
Wind speed (mph)	5.6	5.7	5.7	6.3	6.3	6.2	4.8	4.0	4.7	5.2	5.5	5.6

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Cloud cover (%)	39	43	37	27	25	23
Clear days (≤ 30% cloud)	15	13	16	19	21	21
Partly cloudy days (30–70%)	8	8	9	8	7	6
Cloudy days (≥ 70%)	7	8	7	3	3	3
Relative humidity (%)	48	46	39	30	24	20
Wind speed (mph)	5.6	5.7	5.7	6.3	6.3	6.2

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	55	52	33	26	31	38
Clear days (≤ 30% cloud)	7	8	17	21	18	14
Partly cloudy days (30–70%)	12	14	9	6	7	10
Cloudy days (≥ 70%)	11	10	5	4	5	7
Relative humidity (%)	41	47	43	38	39	47
Wind speed (mph)	4.8	4.0	4.7	5.2	5.5	5.6

Methodology & sources

Temperature & precipitation — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Tucson Wfo (NOAA GHCN station USC00028815), about 3 km from the city centre.

Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.

How we build these numbers →