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October Weather in San Ysidro, United States

Last updated: June 24, 2025

In October, the average temperature in San Ysidro, United States is a comfortable 19°C (66°F), but be prepared for a range: temperatures can dip as low as -2°C (29°F) or soar up to 34°C (93°F). Expect 21 mm (0.8 in) of precipitation over the course of 3 days, and enjoy the moderate average humidity of 75%, making it a truly unique climate experience!

October Temperature in San Ysidro

In October in San Ysidro, the average temperature is 19°C (66°F). The maximum can reach 34°C (93°F), and the minimum can be as low as -2°C (29°F). Travelers should prepare for a wide range of temperatures, so packing layers is essential.

October Weather in San Ysidro: Daily Temperature Highs, Lows, and Averages

The chart illustrates October temperature patterns in San Ysidro, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Ysidro, October typically has an average temperature of 19°C (66°F), with highs reaching up to 34°C (93°F) and lows dropping to around -2°C (29°F).
JanFebMarAprMayJunJulAugSepOctNovDec455058677583838277665546
Data source: Temperature data for San Ysidro generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

October Precipitation in San Ysidro

In San Ysidro in October, the precipitation amount is 21 mm (0.8 in) over a period of 3 days.

October Precipitation Trends in San Ysidro

The chart displays monthly precipitation patterns in San Ysidro, with values for each month alongside October’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how October’s conditions compare to those of other months. In San Ysidro, October typically receives around 21 mm (0.8 inches) of precipitation spread over approximately 3 days.
JanFebMarAprMayJunJulAugSepOctNovDec1315163422313324211313
Data source: Precipitation data for October generated using information from the Copernicus Climate Change Service.
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October Humidity in San Ysidro

In San Ysidro in October humidity is 75%. With an average temperature of 19°C (66°F), this humidity feels like a warm, enveloping blanket, making it slightly uncomfortable for traveling as you navigate through the thick, muggy air.

October Average Humidity in San Ysidro

This chart illustrates the average monthly humidity levels in San Ysidro, with October’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In October, average humidity in San Ysidro is approximately 75%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec79%79%65%55%54%53%55%58%70%75%83%82%
Data source: Humidity data for October generated using information from the Copernicus Climate Change Service.

October UV Index in San Ysidro

In San Ysidro in October, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in San Ysidro.

Maximum UV Index Levels in San Ysidro for October

The chart shows the monthly maximum UV Index (UVI) for San Ysidro in October, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In October, the maximum UV index in San Ysidro typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec5710121213121211865
Data source: San Ysidro October UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How October Weather in San Ysidro Compares to Other Months

Weather in San Ysidro varies notably across the year, with each month offering distinct climate conditions. This page compares October’s weather to other months in San Ysidro, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in San Ysidro, showing how October’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather7°C (45°F)13 mm (0.5 inches)79%moderate
February Weather10°C (50°F)14 mm (0.6 inches)79%high
March Weather14°C (58°F)16 mm (0.6 inches)65%very high
April Weather20°C (67°F)3 mm (0.1 inches)55%extreme
May Weather24°C (75°F)4 mm (0.2 inches)54%extreme
June Weather28°C (84°F)22 mm (0.9 inches)53%extreme
July Weather29°C (84°F)31 mm (1.2 inches)55%extreme
August Weather28°C (83°F)33 mm (1.3 inches)57%extreme
September Weather25°C (77°F)24 mm (0.9 inches)70%extreme
October Weather19°C (66°F)21 mm (0.8 inches)75%very high
November Weather13°C (56°F)13 mm (0.5 inches)83%high
December Weather8°C (47°F)12 mm (0.5 inches)82%moderate

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