Last updated: June 24, 2025
In September, the average temperature in Stamford, United States hovers around 26°C (78°F). While you can expect a pleasant warmth, temperatures can swing from a cool 7°C (45°F) to a sizzling 39°C (102°F). Be prepared for some rain, as the region sees about 87 mm (3.4 in) of precipitation over roughly 6 days. With an average humidity of 64%, it's a month where comfort and climate are intertwined.
In September in Stamford, the average temperature is 26°C (78°F), with maximums reaching 39°C (102°F) and minimums dropping as low as 7°C (45°F). Travelers can expect warm weather, but should be prepared for significant temperature fluctuations, especially in the evenings.
In Stamford in September, the precipitation amount is 87 mm (3.4 in) spread over a period of 6 days.
In Stamford in September humidity is 64%. With an average temperature of 26°C (78°F), this humidity feels like a warm, thick blanket enveloping you, making travel slightly uncomfortable as you navigate the sticky air, leaving you yearning for a refreshing breeze or a cool drink.
In Stamford in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Stamford.
UV Risk Categories
Weather in Stamford varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Stamford, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 7°C (45°F) | 28 mm (1.1 inches) | 77% | moderate |
| February Weather | 8°C (47°F) | 26 mm (1.0 inches) | 76% | high |
| March Weather | 15°C (60°F) | 49 mm (1.9 inches) | 74% | very high |
| April Weather | 18°C (65°F) | 66 mm (2.6 inches) | 75% | very high |
| May Weather | 24°C (75°F) | 79 mm (3.1 inches) | 80% | extreme |
| June Weather | 28°C (83°F) | 60 mm (2.4 inches) | 80% | extreme |
| July Weather | 30°C (86°F) | 31 mm (1.2 inches) | 75% | extreme |
| August Weather | 29°C (85°F) | 44 mm (1.7 inches) | 67% | extreme |
| September Weather | 26°C (78°F) | 87 mm (3.4 inches) | 64% | very high |
| October Weather | 19°C (66°F) | 67 mm (2.6 inches) | 70% | very high |
| November Weather | 13°C (55°F) | 32 mm (1.3 inches) | 82% | high |
| December Weather | 9°C (49°F) | 25 mm (1.0 inches) | 85% | moderate |