Climate and monthly weather forecastPhoenix, AZ
Climate and monthly weather forecast
The climate of Phoenix
Phoenix, part of the Sonoran Desert, lies in the subtropical desert climate or BWh according to the Köppen climate classification. This environment is characterized by extremely hot summers, mild winters, and scant rain.Consistently warm temperatures prevail throughout the year, with highs ranging from a relatively mild 64.2°F (17.9°C) in January to a sweltering 103.6°F (39.8°C) in July. Corresponding lows range from 47.5°F (8.6°C) in January to 84.7°F (29.3°C) in August—indicating no month is devoid of warmth.
Rainfall in Phoenix is rather infrequent with the densest precipitation occurring in the warmer months of July to September—with values amounting to 0.75" (19mm), 0.59" (15mm), and 0.67" (17mm) respectively. During the rest of the year, the city experiences lighter precipitation generally not surpassing half an inch.
Unique to Phoenix is the minimal snowfall it experiences throughout the year, with the only recorded snow in November at a minimal 0.04" (1mm)—rare for many but typical in Phoenix's desert topography. Additionally, the city is illuminated generously during the year, earning between 10 to 14.3 hours of daylight, coupled with a high UV index that peaks between May and August at an 8.
The best time to visit Phoenix
When to visit Phoenix largely depends on heat tolerance and the desired activities. November through April is the city’s peak season due to mild and pleasant temperatures. During this time, temperatures range from highs of 64.2°F (17.9°C) to 90.9°F (32.7°C) and lows of 47.5°F (8.6°C) to 67.6°F (19.8°C)—an ideal climate for outdoor exploration or lounging by the pool without being overwhelmed by summer's ferocious heat.Moreover, these months boast moderate humidity (between 33% to 43%), lower UV index (between 3 and 6), and longer sunshine hours (varying between 7.1 and 11.9 hours), making them the most favorable for visitors.
The worst time to visit Phoenix
Despite Phoenix's attractive year-round warmth, the months of June to September can be excessively hot for most people. During these months, average high temperatures soar beyond 100°F (37.8°C). Wind speed slightly increases during this season (from 5.9mph (9.5km/h) to 6.4mph (10.3km/h)), but this does little to mitigate the intense heat.Additionally, humidity drops to its lowest between 16% to 19%, and a higher UV index of 8 potentially raises the risk of sunburn or heatstroke if proper precautions are not taken. Therefore, unless seeking the full desert heat experience, these months are perhaps best avoided.
Spring weather in Phoenix
During March to May, Phoenix begins its transition from mild to hot weather. Temperatures gradually escalate with average highs jumping from 76.1°F (24.5°C) in March to 90.9°F (32.7°C) in May. Corresponding lows also rise from 55.9°F (13.3°C) to 67.6°F (19.8°C).This season records little rainfall, with the driest month being May registering just 0.08" (2mm). Moreover, daylight hours increase (from 12 to 13.9 hours) along with the UV index, starting at 5 in March and reaching 8 in May.
Summer weather in Phoenix
Summer is intimidating in Phoenix, with June to September featuring the year's hottest temperatures. Daytime highs in these months easily surpass 100°F (37.8°C), and nighttime lows rarely drop below the mid-70s°F.The summer months also yield the highest rainfall of the year, with July's 0.75" (19mm) being the peak. However, even at its highest, rainfall remains quite minimal. This season also experiences the highest UV index of 8.
Autumn weather in Phoenix
Autumnal temperatures bring some respite from the summer heat, with averages receding gradually from September to November. Highs dip from 96.3°F (35.7°C) to 73.6°F (23.1°C) and lows from 78.8°F (26°C) to 56.3°F (13.5°C).Rainfall during this period is slightly lower than summer, but it still maintains a consistent presence, reaching its pinnacle in September at 0.67" (17mm). UV index begins to decrease, registering a 7 in September and dropping to 4 by November.
Winter weather in Phoenix
Phoenix embraces winter in a unique way, with temperatures staying comfortably warm compared to most regions. December to February features highs in the 60s°F and lows in the 40s°F and 50s°F—quite mild for a typical winter.These cooler months bring a marginally higher chance of rain, with December and February both registering 0.59" (15mm). However, the overall climatic conditions remain predominantly dry, showing Phoenix's consistent adherence to its desert climate categorization.
Weather in January
Phoenix, Arizona, ushers in the new year with mild winter conditions, making outdoor activities rather pleasant. January weather exhibits a stark contrast to the sizzling summer months the city is known for. Reaching to a mild 64.2°F (17.9°C), the city enjoys its second-lowest average high temperature. Weather in January »Weather in February
Bidding adieu to January’s cool tones, February in Phoenix brings marginally warmer temperatures. This transitional weather marks the start of moderate spring conditions. The average high temperature leaps to 67.6°F (19.8°C), slightly warmer compared to the previous month. Weather in February »Weather in March
March witnesses a continued gradual increase in temperature as Phoenix moves further into spring. This month exposes Phoenix's desert characteristics with climbing temperatures and falling humidity levels. The city welcomes the warmer 76.1°F (24.5°C) average high temperature, providing bounteous warmth without the intense heat of summer. Weather in March »Weather in April
April in Phoenix, Arizona, encapsulates the end of spring, paving the way for the fast-approaching summer. The city experiences a noteworthy jump in temperatures, signaling the start of stark sunny weather. Soaring to 83.1°F (28.4°C), it sets the stage for the high temperatures that define Phoenix's weather. Weather in April »Weather in May
May stands as the threshold to the sweltering summer that Phoenix is famous for. As the city transitions into the hotter part of the year, the dry and sunny weather becomes prominent. The temperature index hits 90.9°F (32.7°C), indicating an impending scorching summer. Weather in May »Weather in June
In June, Phoenix fully embraces its notoriously torrid summer weather. The city hits triple-digit temperatures, characterized by sunny days and almost no rain. Predominantly dry, the temperature reaches an average high of 102°F (38.9°C), making June one of the hottest months of the year. Weather in June »Weather in July
July in Phoenix prevails as the pinnacle of the city's hot, arid summer. The city swims in extremely high temperatures and sun-drunk days. Topping at 103.6°F (39.8°C), it holds the record for the highest average high of the year. An inevitable increase in rainfall provides the first sign of respite from the unforgiving dry spell. Weather in July »Weather in August
August in Phoenix continues to be dominated by the summer heat, though slight hints of a reprieve become apparent. It segments in the last phase of the intense summer punctuated by occasional thunderstorms. Marginally lower than July, the average high temperature hangs around 102.6°F (39.2°C). Weather in August »Weather in September
The arrival of September in Phoenix marks the outset of milder temperatures and reduced humidity. The city starts to witness a notable drop in temperatures, signaling the retreat of the sweltering summer with a distinct autumn breeze. Weather in September »Weather in October
October in Phoenix is distinguished by diversely agreeable weather, marking the city's transition into vibrant autumn. The heat of summer is exchanged for the milder, cooler temperature spectrum. Compared to September, the city sees a significant drop in the average high temperature, sliding down to 85.1°F (29.5°C). Weather in October »Weather in November
As fall permeates Phoenix in November, the city takes pleasure in the mild and enjoyable weather it offers. A significant shift in temperature accompanies the departure of October. The temperature takes another drop, reaching a pleasant average high of 73.6°F (23.1°C). Weather in November »Weather in December
December in Phoenix rounds off the year under the gentle glow of winter sun. As the city greets the last month of the year, a soothing chill fills the air. Average high temperatures drop even further to a bearable 63°F (17.2°C), confirming the onset of winter. Weather in December »Updated: Jul 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
In Phoenix, during the entire year, the rain falls for 44.6 days and collects up to 5.04" (128mm) of precipitation.
January through August, October through December are months without snowfall.
In Phoenix, during the entire year, snow aggregates up to 0.04" (1mm).
The months with the least rainfall in Phoenix, Arizona, are May and June Rain falls for 1.3 days and accumulates 0.08" (2mm) of rain.
The months with the highest UV index are May through August, with an average maximum UV index of 8.
With an average relative humidity of 16%, June is the least humid month.
June has the longest days of the year, with an average of 14h and 18min of daylight.
June has the most sunshine of the year, with an average of 12.1h of sunshine.
In Phoenix, July is identified by the average highest temperatures, reaching a peak of 103.6°F (39.8°C) and a low of 84°F (28.9°C).
The month with the most rainfall is July, when the rain falls for 7.8 days and typically aggregates up to 0.75" (19mm) of precipitation.
September is the only month when snow falls.
September is the month with the most snowfall. Snow falls for 0.1 days and accumulates 0.04" (1mm) of snow.
In Phoenix, December is the month with the lowest recorded average temperatures, measuring a high of 63°F (17.2°C) and a low of 47.8°F (8.8°C).
The most humid month is December, with an average relative humidity of 43%.
December has the shortest days of the year, with an average of 10h and 0min of daylight.
Phoenix does not observe Daylight Saving Time (DST). MST timezone is used throughout the entire year.
December has the least sunshine of the year, with an average of 6.8h of sunshine.
The month with the lowest UV index is December, with an average maximum UV index of 3.
Average temperature
Phoenix, AZ
The warmest month (with the highest average high temperature) is July (103.6°F).
The month with the lowest average high temperature is December (63°F).
The month with the highest average low temperature is August (84.7°F).
The coldest month (with the lowest average low temperature) is January (47.5°F).
Average pressure
Phoenix, AZ
- Average pressure in January:
30.09"Hg - Average pressure in February:
30.02"Hg - Average pressure in March:
29.97"Hg - Average pressure in April:
29.88"Hg - Average pressure in May:
29.84"Hg - Average pressure in June:
29.81"Hg
- Average pressure in July:
29.87"Hg - Average pressure in August:
29.87"Hg - Average pressure in September:
29.87"Hg - Average pressure in October:
29.91"Hg - Average pressure in November:
30.01"Hg - Average pressure in December:
30.06"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.81"Hg).
Average wind speed
Phoenix, AZ
- Average wind speed in January:
4.5mph - Average wind speed in February:
4.7mph - Average wind speed in March:
5.3mph - Average wind speed in April:
6.4mph - Average wind speed in May:
6.3mph - Average wind speed in June:
5.9mph
- Average wind speed in July:
6mph - Average wind speed in August:
5.3mph - Average wind speed in September:
5.2mph - Average wind speed in October:
4.9mph - Average wind speed in November:
4.7mph - Average wind speed in December:
4.3mph
The windiest month (with the highest average wind speed) is April (6.4mph).
The calmest month (with the lowest average wind speed) is December (4.3mph).
Average humidity
Phoenix, AZ
The month with the highest relative humidity is December (43%).
The month with the lowest relative humidity is June (16%).
Average rainfall
Phoenix, AZ
- Average rainfall in January:
0.28" - Average rainfall in February:
0.43" - Average rainfall in March:
0.43" - Average rainfall in April:
0.12" - Average rainfall in May:
0.08" - Average rainfall in June:
0.08"
- Average rainfall in July:
0.75" - Average rainfall in August:
0.59" - Average rainfall in September:
0.67" - Average rainfall in October:
0.67" - Average rainfall in November:
0.35" - Average rainfall in December:
0.59"
The wettest month (with the highest rainfall) is July (0.75").
The driest months (with the least rainfall) are May and June (0.08").
Average rainfall days
Phoenix, AZ
- Average rainfall days in January:
3 days - Average rainfall days in February:
3.6 days - Average rainfall days in March:
3.5 days - Average rainfall days in April:
2.2 days - Average rainfall days in May:
1.3 days - Average rainfall days in June:
0.8 days
- Average rainfall days in July:
7.8 days - Average rainfall days in August:
7.2 days - Average rainfall days in September:
4.7 days - Average rainfall days in October:
3 days - Average rainfall days in November:
2.5 days - Average rainfall days in December:
5 days
The month with the highest number of rainy days is July (7.8 days).
The month with the least rainy days is June (0.8 days).
Average snowfall
Phoenix, AZ
The month with the highest snowfall is September (0.04").
The months with the least snowfall are January, February, March, April, May, June, July, August, October, November and December (0").
Average snowfall days
Phoenix, AZ
- Average snowfall days in January:
0 days - Average snowfall days in February:
0 days - Average snowfall days in March:
0 days - Average snowfall days in April:
0 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0.1 days - Average snowfall days in October:
0 days - Average snowfall days in November:
0 days - Average snowfall days in December:
0 days
The month with the highest number of snowfall days is September (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, October, November and December (0 days).
Average daylight / Average sunshine
Phoenix, AZ
- Average daylight in January:
10h and 12min - Average daylight in February:
11h and 0min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 0min - Average daylight in May:
13h and 54min - Average daylight in June:
14h and 18min
- Average daylight in July:
14h and 6min - Average daylight in August:
13h and 24min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 18min - Average daylight in November:
10h and 24min - Average daylight in December:
10h and 0min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in January:
7h and 6min - Average sunshine in February:
9h and 6min - Average sunshine in March:
9h and 12min - Average sunshine in April:
10h and 48min - Average sunshine in May:
11h and 54min - Average sunshine in June:
12h and 6min
- Average sunshine in July:
12h and 0min - Average sunshine in August:
12h and 0min - Average sunshine in September:
9h and 42min - Average sunshine in October:
8h and 12min - Average sunshine in November:
7h and 18min - Average sunshine in December:
6h and 48min
The month with the most sunshine is June (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 48min).
Average sunshine days
Phoenix, AZ
- Average sunshine days in January:
27.3 days - Average sunshine days in February:
24.2 days - Average sunshine days in March:
28.3 days - Average sunshine days in April:
28.3 days - Average sunshine days in May:
29.2 days - Average sunshine days in June:
28.6 days
- Average sunshine days in July:
21.1 days - Average sunshine days in August:
21.8 days - Average sunshine days in September:
23.7 days - Average sunshine days in October:
26.9 days - Average sunshine days in November:
27.2 days - Average sunshine days in December:
25.5 days
The month with the most sunshine days is May (29.2 days).
The month with the least sunshine days is July (21.1 days).
Average UV index
Phoenix, AZ
The months with the highest UV index are May, June, July and August (UV index 8).
The month with the lowest UV index is December (UV index 3).
Average cloud cover
Phoenix, AZ
The month with the most cloud cover is December (Cloud cover 21).
The month with the least cloud cover is June (Cloud cover 5).
Average visibility
Phoenix, AZ
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
