Climate and monthly weather forecastRialto, CA
Climate and monthly weather forecast
Weather in January
January in Rialto, California, is an enjoyable winter month, with an average temperature ranging between min 44.2°F (6.8°C) and max 62.4°F (16.9°C). As Rialto, California, welcomes January, the average high-temperature stabilizes at a comfortable 62.4°F (16.9°C), showing little deviation from December's 59.9°F (15.5°C). Weather in January »Weather in February
The last month of the winter, February, is another comfortable month in Rialto, California, with an average temperature ranging between max 62.4°F (16.9°C) and min 43.3°F (6.3°C). With the dawn of February, Rialto witnesses an average high-temperature of a still enjoyable 62.4°F (16.9°C), on par with January. Weather in February »Weather in March
March, the first month of the spring in Rialto, is also an enjoyable month, with temperature in the range of an average low of 45.3°F (7.4°C) and an average high of 66.9°F (19.4°C). Rialto, California, marks the arrival of March with an average high-temperature of a still comfortable 66.9°F (19.4°C), hardly different from February's 62.4°F (16.9°C). Weather in March »Weather in April
April in Rialto, California, is an agreeable spring month, with an average temperature fluctuating between 48.2°F (9°C) and 71.8°F (22.1°C). As Rialto, California, steps into April, the average high-temperature is measured at a pleasant 71.8°F (22.1°C), displaying minor differences from March's 66.9°F (19.4°C). Weather in April »Weather in May
May, the last month of the spring in Rialto, is a warm month, with an average temperature varying between 52.3°F (11.3°C) and 76.6°F (24.8°C). In May, Rialto notes an average high-temperature of a warm 76.6°F (24.8°C), hardly different from the preceding month. Weather in May »Weather in June
June, the first month of the summer in Rialto, is also a moderately hot month, with an average temperature fluctuating between 85.5°F (29.7°C) and 57.7°F (14.3°C). In Rialto, the onset of June comes with a modest high-temperature shift, transitioning from May's warm 76.6°F (24.8°C) to a still moderately hot 85.5°F (29.7°C). Weather in June »Weather in July
July in Rialto, California, is a hot summer month, with an average temperature fluctuating between 64.2°F (17.9°C) and 91.2°F (32.9°C). Rialto in July observes a minor temperature shift, with average high-temperatures adjusting from a moderately hot 85.5°F (29.7°C) in June to a tropical 91.2°F (32.9°C). Weather in July »Weather in August
The last month of the summer, August, is also a hot month in Rialto, California, with an average temperature varying between 65.8°F (18.8°C) and 91.9°F (33.3°C). Rialto experiences its highest average temperatures in August, reaching a peak of 91.9°F (33.3°C) and a minimum of 65.8°F (18.8°C). Weather in August »Weather in September
September, the first month of the autumn in Rialto, is still a hot month, with temperature in the range of an average high of 87.8°F (31°C) and an average low of 63°F (17.2°C). The arrival of September brings an average high-temperature of a still hot 87.8°F (31°C), closely following the temperature pattern of August. Weather in September »Weather in October
October, like September, in Rialto, California, is a moderately hot autumn month, with temperature in the range of an average high of 77.9°F (25.5°C) and an average low of 56.1°F (13.4°C). The shift to October brings a decrease in the average high-temperature, falling from a hot 87.8°F (31°C) in September to a warm 77.9°F (25.5°C). Weather in October »Weather in November
The last month of the autumn, November, is also an agreeable month in Rialto, California, with temperature in the range of an average high of 68.9°F (20.5°C) and an average low of 49.1°F (9.5°C). Rialto's November weather shows a moderate shift in high-temperatures, falling from October's warm 77.9°F (25.5°C) to a pleasant 68.9°F (20.5°C). Weather in November »Weather in December
December, the first month of the winter in Rialto, is still a mild month, with an average temperature fluctuating between 59.9°F (15.5°C) and 43.5°F (6.4°C). In Rialto, California, December records the lowest average temperatures, peaking at 59.9°F (15.5°C) and reaching a low of 43.5°F (6.4°C). Weather in December »Updated: Feb 9, 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 Rialto, during the entire year, the rain falls for 43.5 days and collects up to 5.43" (138mm) of precipitation.
In Rialto, California, snow does not fall in January, March through December.
In Rialto, California, during the entire year, snow falls for 0.1 days.
February and March, with an average relative humidity of 52%, are most humid months.
The months with the most rainfall are February and December, with an average 1.14" (29mm) of precipitation.
The only month with snowfall is February.
February has the most snowfall days of the year in Rialto, California. Snow falls for 0.1 days.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Rialto, California, and the time zone changes from PST to PDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from PDT to PST.
June is the month with the least rainfall. Rain falls for 1.3 days and accumulates 0.04" (1mm) of precipitation.
With an average of 14h and 24min of daylight, June has the longest days of the year in Rialto, California.
The months with the most sunshine are June and July, with an average of 12.1h of sunshine.
June through August, with an average maximum UV index of 7, are months with the highest UV index in Rialto, California.
August, with an average high of 91.9°F (33.3°C) and a low of 65.8°F (18.8°C), signifies the warmest month of the year.
The least humid month is August, with an average relative humidity of 38%.
Temperature records in Rialto, California, mark December as the coldest month, with highs averaging 59.9°F (15.5°C) and lows at 43.5°F (6.4°C).
With an average of 9h and 54min of daylight, December has the shortest days of the year in Rialto, California.
With an average of 6.9h of sunshine, December has the least sunshine of the year.
With an average maximum UV index of 3, December is the month with the lowest UV index.
Average temperature
Rialto, CA
The warmest month (with the highest average high temperature) is August (91.9°F).
The month with the lowest average high temperature is December (59.9°F).
The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is February (43.3°F).
Average pressure
Rialto, CA
- Average pressure in January:
30.1"Hg - Average pressure in February:
30.04"Hg - Average pressure in March:
30.01"Hg - Average pressure in April:
29.94"Hg - Average pressure in May:
29.89"Hg - Average pressure in June:
29.85"Hg
- Average pressure in July:
29.88"Hg - Average pressure in August:
29.87"Hg - Average pressure in September:
29.87"Hg - Average pressure in October:
29.94"Hg - Average pressure in November:
30.03"Hg - Average pressure in December:
30.07"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed
Rialto, CA
- Average wind speed in January:
5.4mph - Average wind speed in February:
5.2mph - Average wind speed in March:
5.5mph - Average wind speed in April:
6.2mph - Average wind speed in May:
6mph - Average wind speed in June:
5.7mph
- Average wind speed in July:
5.2mph - Average wind speed in August:
4.8mph - Average wind speed in September:
4.5mph - Average wind speed in October:
4.9mph - Average wind speed in November:
5.2mph - Average wind speed in December:
5.3mph
The windiest month (with the highest average wind speed) is April (6.2mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).
Average humidity
Rialto, CA
The months with the highest relative humidity are February and March (52%).
The month with the lowest relative humidity is August (38%).
Average rainfall
Rialto, CA
- Average rainfall in January:
0.59" - Average rainfall in February:
1.14" - Average rainfall in March:
0.51" - Average rainfall in April:
0.59" - Average rainfall in May:
0.12" - Average rainfall in June:
0.04"
- Average rainfall in July:
0.28" - Average rainfall in August:
0.16" - Average rainfall in September:
0.12" - Average rainfall in October:
0.16" - Average rainfall in November:
0.59" - Average rainfall in December:
1.14"
The wettest months (with the highest rainfall) are February and December (1.14").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days
Rialto, CA
- Average rainfall days in January:
4.8 days - Average rainfall days in February:
4.6 days - Average rainfall days in March:
5.3 days - Average rainfall days in April:
5.2 days - Average rainfall days in May:
3.3 days - Average rainfall days in June:
1.3 days
- Average rainfall days in July:
3.6 days - Average rainfall days in August:
2.2 days - Average rainfall days in September:
2.5 days - Average rainfall days in October:
2.3 days - Average rainfall days in November:
2.9 days - Average rainfall days in December:
5.5 days
The month with the highest number of rainy days is December (5.5 days).
The month with the least rainy days is June (1.3 days).
Average snowfall days
Rialto, CA
- Average snowfall days in January:
0 days - Average snowfall days in February:
0.1 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 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 February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight / Average sunshine
Rialto, CA
- 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 6min - Average daylight in May:
14h and 0min - Average daylight in June:
14h and 24min
- Average daylight in July:
14h and 12min - 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:
9h and 54min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in January:
7h and 6min - Average sunshine in February:
7h and 0min - Average sunshine in March:
9h and 0min - Average sunshine in April:
11h and 24min - Average sunshine in May:
11h and 48min - Average sunshine in June:
12h and 6min
- Average sunshine in July:
12h and 6min - Average sunshine in August:
12h and 0min - Average sunshine in September:
10h and 42min - Average sunshine in October:
9h and 0min - Average sunshine in November:
7h and 18min - Average sunshine in December:
6h and 54min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 54min).
Average sunshine days
Rialto, CA
- Average sunshine days in January:
25.1 days - Average sunshine days in February:
22.6 days - Average sunshine days in March:
25.3 days - Average sunshine days in April:
24.9 days - Average sunshine days in May:
25.8 days - Average sunshine days in June:
27.8 days
- Average sunshine days in July:
23.3 days - Average sunshine days in August:
25.4 days - Average sunshine days in September:
24.7 days - Average sunshine days in October:
27.2 days - Average sunshine days in November:
26.3 days - Average sunshine days in December:
24.5 days
The month with the most sunshine days is June (27.8 days).
The month with the least sunshine days is February (22.6 days).
Average UV index
Rialto, CA
The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover
Rialto, CA
The month with the most cloud cover is December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility
Rialto, CA
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).
