Climate and monthly weather forecastSan Ysidro, CA
Climate and monthly weather forecast
Weather in January
January, the same as December, is another enjoyable winter month in San Ysidro, California, with an average temperature varying between 50.9°F (10.5°C) and 65.5°F (18.6°C). As December transitions into January, the average high-temperature rests at a still comfortable 65.5°F (18.6°C), maintaining a close resemblance to the previous month. Weather in January »Weather in February
The last month of the winter, February, is another refreshing month in San Ysidro, California, with an average temperature ranging between max 64.4°F (18°C) and min 50.2°F (10.1°C). San Ysidro observes a minor difference in average high-temperatures between January's 65.5°F (18.6°C) and February's 64.4°F (18°C). Weather in February »Weather in March
The first month of the spring, March, is still a refreshing month in San Ysidro, California, with temperature in the range of an average high of 66.6°F (19.2°C) and an average low of 51.3°F (10.7°C). In San Ysidro, March's average high-temperature stands at a still refreshing 66.6°F (19.2°C), closely related to the preceding month. Weather in March »Weather in April
April in San Ysidro, California, is a pleasant spring month, with an average temperature fluctuating between 53.1°F (11.7°C) and 68.5°F (20.3°C). The transition into April reveals an average high-temperature of an agreeable 68.5°F (20.3°C), mirroring a close resemblance to March. Weather in April »Weather in May
The last month of the spring, May, is another pleasant month in San Ysidro, California, with an average temperature varying between 55.9°F (13.3°C) and 69.8°F (21°C). San Ysidro starts May with an average high-temperature of a still pleasant 69.8°F (21°C), a minor shift from April's 68.5°F (20.3°C). Weather in May »Weather in June
June, the first month of the summer in San Ysidro, is a warm month, with an average temperature varying between 74.1°F (23.4°C) and 59.2°F (15.1°C). At the start of June, San Ysidro's average high-temperature reaches a warm 74.1°F (23.4°C), subtly different from the preceding month. Weather in June »Weather in July
July, the same as June, is another warm summer month in San Ysidro, California, with an average temperature ranging between min 64.9°F (18.3°C) and max 79°F (26.1°C). The commencement of July notes an average high-temperature of a still warm 79°F (26.1°C), exhibiting little difference from the previous month. Weather in July »Weather in August
The last month of the summer, August, is another warm month in San Ysidro, California, with an average temperature varying between 81.1°F (27.3°C) and 66.7°F (19.3°C). August, recording an average high temperature of 81.1°F (27.3°C) and a low temperature of 66.7°F (19.3°C), is San Ysidro's warmest month. For August, the heat index is evaluated at 84.2°F (29°C). Weather in August »Weather in September
The first month of the autumn, September, is also a moderately hot month in San Ysidro, California, with an average temperature varying between 80.1°F (26.7°C) and 65.5°F (18.6°C). A minimal variation is noted in San Ysidro's average high-temperature at the onset of September, reaching a still moderately hot 80.1°F (26.7°C) from August's 81.1°F (27.3°C). Weather in September »Weather in October
October, like September, in San Ysidro, California, is a moderately hot autumn month, with an average temperature fluctuating between 61.2°F (16.2°C) and 75.6°F (24.2°C). The arrival of October brings an average high-temperature of a still warm 75.6°F (24.2°C), subtly diverging from September's 80.1°F (26.7°C). Weather in October »Weather in November
The last month of the autumn, November, is also an agreeable month in San Ysidro, California, with temperature in the range of an average high of 70.3°F (21.3°C) and an average low of 56.1°F (13.4°C). At the start of November, San Ysidro's average high-temperature reaches an agreeable 70.3°F (21.3°C), subtly different from the preceding month. Weather in November »Weather in December
The first month of the winter, December, is still a comfortable month in San Ysidro, California, with an average temperature fluctuating between 64°F (17.8°C) and 50.4°F (10.2°C). With average high temperatures of 64°F (17.8°C) and lows of 50.4°F (10.2°C), December is the coldest month. Weather in December »Updated: Jun 26, 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
Throughout the year, there are 57.8 rainfall days, and 7.28" (185mm) of precipitation is accumulated.
The months with the lowest UV index in San Ysidro are January, February, November and December, with an average maximum UV index of 4.
February is the month with the most rainfall. Rain falls for 6.3 days and accumulates 1.5" (38mm) of precipitation.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, 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.
The most humid month is May, with an average relative humidity of 68%.
June is the month with the least rainfall. Rain falls for 1.8 days and accumulates 0.08" (2mm) of precipitation.
The month with the longest days is June, with an average of 14h and 18min of daylight.
The months with the highest UV index are June through September, with an average maximum UV index of 6.
With an average of 12h of sunshine, July has the most sunshine of the year.
In San Ysidro, the peak average temperatures are observed in August, with a high of 81.1°F (27.3°C) and a low of 66.7°F (19.3°C).
November is the least humid month, with an average relative humidity of 55%.
The coldest period tends to be December, when average temperatures fluctuate between a high of 64°F (17.8°C) and a low of 50.4°F (10.2°C).
With an average of 10h and 6min of daylight, December has the shortest days of the year.
With an average of 6.6h of sunshine, December has the least sunshine of the year.
Average temperature
San Ysidro, CA
The warmest month (with the highest average high temperature) is August (81.1°F).
The month with the lowest average high temperature is December (64°F).
The month with the highest average low temperature is August (66.7°F).
The coldest month (with the lowest average low temperature) is February (50.2°F).
Average pressure
San Ysidro, CA
- Average pressure in January:
30.08"Hg - Average pressure in February:
30.04"Hg - Average pressure in March:
30.02"Hg - Average pressure in April:
29.96"Hg - Average pressure in May:
29.92"Hg - Average pressure in June:
29.88"Hg
- Average pressure in July:
29.91"Hg - Average pressure in August:
29.88"Hg - Average pressure in September:
29.88"Hg - Average pressure in October:
29.93"Hg - Average pressure in November:
30.01"Hg - Average pressure in December:
30.06"Hg
The month with the highest atmospheric pressure is January (30.08"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.88"Hg).
Average wind speed
San Ysidro, CA
- Average wind speed in January:
5.2mph - Average wind speed in February:
5.7mph - Average wind speed in March:
5.6mph - Average wind speed in April:
6mph - Average wind speed in May:
6mph - Average wind speed in June:
5.3mph
- Average wind speed in July:
5.2mph - Average wind speed in August:
5.1mph - Average wind speed in September:
5mph - Average wind speed in October:
4.8mph - Average wind speed in November:
5.1mph - Average wind speed in December:
5.2mph
The windiest months (with the highest average wind speed) are April and May (6mph).
The calmest month (with the lowest average wind speed) is October (4.8mph).
Average humidity
San Ysidro, CA
The month with the highest relative humidity is May (68%).
The month with the lowest relative humidity is November (55%).
Average rainfall
San Ysidro, CA
- Average rainfall in January:
0.79" - Average rainfall in February:
1.5" - Average rainfall in March:
0.79" - Average rainfall in April:
0.43" - Average rainfall in May:
0.39" - Average rainfall in June:
0.08"
- Average rainfall in July:
0.35" - Average rainfall in August:
0.35" - Average rainfall in September:
0.35" - Average rainfall in October:
0.16" - Average rainfall in November:
0.83" - Average rainfall in December:
1.26"
The wettest month (with the highest rainfall) is February (1.5").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days
San Ysidro, CA
- Average rainfall days in January:
5.1 days - Average rainfall days in February:
6.3 days - Average rainfall days in March:
7.5 days - Average rainfall days in April:
6.3 days - Average rainfall days in May:
5.4 days - Average rainfall days in June:
1.8 days
- Average rainfall days in July:
4.6 days - Average rainfall days in August:
3.2 days - Average rainfall days in September:
4.5 days - Average rainfall days in October:
2.8 days - Average rainfall days in November:
4.3 days - Average rainfall days in December:
6 days
The month with the highest number of rainy days is March (7.5 days).
The month with the least rainy days is June (1.8 days).
Average daylight / Average sunshine
San Ysidro, CA
- Average daylight in January:
10h and 18min - 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 48min - Average daylight in June:
14h and 18min
- Average daylight in July:
14h and 0min - Average daylight in August:
13h and 18min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 24min - Average daylight in November:
10h and 30min - Average daylight in December:
10h and 6min
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 6min).
- Average sunshine in January:
6h and 48min - Average sunshine in February:
6h and 42min - Average sunshine in March:
8h and 36min - Average sunshine in April:
10h and 42min - Average sunshine in May:
10h and 36min - Average sunshine in June:
11h and 48min
- Average sunshine in July:
12h and 0min - Average sunshine in August:
11h and 54min - Average sunshine in September:
10h and 12min - Average sunshine in October:
8h and 48min - Average sunshine in November:
7h and 6min - Average sunshine in December:
6h and 36min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 36min).
Average sunshine days
San Ysidro, CA
- Average sunshine days in January:
24.9 days - Average sunshine days in February:
20.8 days - Average sunshine days in March:
22.7 days - Average sunshine days in April:
23.3 days - Average sunshine days in May:
23.8 days - Average sunshine days in June:
27.8 days
- Average sunshine days in July:
23.7 days - Average sunshine days in August:
24 days - Average sunshine days in September:
24.3 days - Average sunshine days in October:
26.2 days - Average sunshine days in November:
24.6 days - Average sunshine days in December:
23.5 days
The month with the most sunshine days is June (27.8 days).
The month with the least sunshine days is February (20.8 days).
Average UV index
San Ysidro, CA
The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 4).
Average cloud cover
San Ysidro, CA
The months with the most cloud cover are March and December (Cloud cover 25).
The month with the least cloud cover is August (Cloud cover 8).
Average visibility
San Ysidro, 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).
