Last updated: June 24, 2025
In Saint James, United States, the average temperature in September hovers around 18°C (65°F). While you can expect a minimum of 2°C (37°F), the mercury may soar to a maximum of 33°C (91°F). Prepare for about 128 mm (5.1 in) of precipitation spread over 9 days, and don't forget to account for the average humidity level of 75%—it’s definitely a month to be comfortable and prepared for any weather!
In September in Saint James, the average temperature is 18°C (65°F). The maximum can reach 33°C (91°F), while the minimum can be as low as 2°C (37°F). This makes it a great time for travelers to enjoy a variety of outdoor activities, just be sure to pack for both warm and cooler weather.
In Saint James in September, the precipitation amount is 128 mm (5.1 in) over the course of 9 days.
In Saint James in September, humidity is 75%. With an average temperature of 18°C (65°F), this humidity feels like a warm, enveloping blanket that can make outdoor exploration feel a bit stifling, potentially leading to discomfort during travel activities.
In Saint James 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 Saint James.
UV Risk Categories
Weather in Saint James varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Saint James, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -8°C (17°F) | 32 mm (1.3 inches) | 82% | moderate |
| February Weather | -9°C (17°F) | 32 mm (1.3 inches) | 84% | moderate |
| March Weather | 1°C (34°F) | 68 mm (2.7 inches) | 80% | moderate |
| April Weather | 7°C (44°F) | 91 mm (3.6 inches) | 81% | very high |
| May Weather | 15°C (60°F) | 137 mm (5.4 inches) | 74% | very high |
| June Weather | 22°C (72°F) | 120 mm (4.7 inches) | 80% | very high |
| July Weather | 23°C (74°F) | 124 mm (4.9 inches) | 80% | very high |
| August Weather | 21°C (71°F) | 116 mm (4.6 inches) | 77% | very high |
| September Weather | 18°C (65°F) | 128 mm (5.1 inches) | 75% | very high |
| October Weather | 9°C (49°F) | 97 mm (3.8 inches) | 80% | moderate |
| November Weather | 1°C (35°F) | 33 mm (1.3 inches) | 87% | moderate |
| December Weather | -4°C (25°F) | 43 mm (1.7 inches) | 83% | low |