Last updated: June 24, 2025
In Castalia, United States, the average temperature in September hovers around 20°C (69°F), with a minimum dropping to 10°C (50°F) and a maximum reaching up to 31°C (88°F). Expect 70 mm (2.8 in) of precipitation spread over about 9 days, contributing to an average humidity level of 78%. Prepare for a warm month with a mix of sunny and wet days!
In September in Castalia, the average temperature is 20°C (69°F). Maximums can reach 31°C (88°F), and minimums can be as low as 10°C (50°F). This moderate climate makes Castalia an ideal destination for travelers seeking pleasant weather and enjoyable outdoor activities.
In Castalia in September, the total precipitation amount is 70 mm (2.8 in) spread over 9 days.
In Castalia in September, humidity is 78%. With an average temperature of 20°C (69°F), this humidity feels like a warm, enveloping blanket, making travel somewhat uncomfortable as sweat clings to your skin and the air feels thick and heavy, urging you to seek out shaded areas and refreshing drinks.
In Castalia in September, 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 Castalia.
UV Risk Categories
Weather in Castalia varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Castalia, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -1°C (30°F) | 76 mm (3.0 inches) | 88% | moderate |
| February Weather | -1°C (31°F) | 83 mm (3.3 inches) | 87% | moderate |
| March Weather | 3°C (39°F) | 87 mm (3.4 inches) | 87% | high |
| April Weather | 9°C (48°F) | 106 mm (4.2 inches) | 87% | very high |
| May Weather | 16°C (60°F) | 124 mm (4.9 inches) | 81% | very high |
| June Weather | 21°C (71°F) | 108 mm (4.3 inches) | 82% | very high |
| July Weather | 24°C (76°F) | 121 mm (4.8 inches) | 81% | very high |
| August Weather | 23°C (74°F) | 82 mm (3.2 inches) | 78% | very high |
| September Weather | 20°C (69°F) | 70 mm (2.8 inches) | 78% | very high |
| October Weather | 14°C (58°F) | 99 mm (3.9 inches) | 82% | high |
| November Weather | 6°C (42°F) | 98 mm (3.9 inches) | 89% | moderate |
| December Weather | 2°C (35°F) | 72 mm (2.8 inches) | 86% | low |