Last updated: June 24, 2025
In Hartwick, United States, the average temperature in September hovers around 16°C (62°F). However, be prepared for temperature swings, as it can dip to a chilly -1°C (31°F) or soar to a balmy 31°C (88°F). During this month, you'll likely experience 102 mm (4.0 in) of precipitation over about 10 days, with an average humidity level of 78%.
In September in Hartwick, the average temperature is 16°C (62°F), with maximums reaching up to 31°C (88°F) and minimums dropping as low as -1°C (31°F). This variability in temperature makes it advisable for travelers to pack both light clothing for warm days and layers for cooler nights.
In Hartwick in September, the total precipitation amount is 102 mm (4.0 in) falling over the course of 10 days.
In Hartwick in September, humidity is 78%. With an average temperature of 16°C (62°F), this humidity feels like a warm blanket wrapping around you, making outdoor activities enjoyable yet slightly sticky. Travelers may find the weather pleasantly mild, though they'll appreciate having light, breathable clothing on hand to stay comfortable while exploring.
In Hartwick 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 Hartwick.
UV Risk Categories
Weather in Hartwick varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Hartwick, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -5°C (23°F) | 84 mm (3.3 inches) | 90% | moderate |
| February Weather | -3°C (27°F) | 99 mm (3.9 inches) | 90% | moderate |
| March Weather | 0°C (33°F) | 89 mm (3.5 inches) | 87% | high |
| April Weather | 7°C (44°F) | 121 mm (4.8 inches) | 88% | very high |
| May Weather | 14°C (57°F) | 125 mm (4.9 inches) | 82% | very high |
| June Weather | 18°C (65°F) | 118 mm (4.7 inches) | 79% | very high |
| July Weather | 21°C (70°F) | 146 mm (5.7 inches) | 78% | very high |
| August Weather | 20°C (68°F) | 127 mm (5.0 inches) | 76% | very high |
| September Weather | 16°C (62°F) | 102 mm (4.0 inches) | 78% | very high |
| October Weather | 11°C (51°F) | 163 mm (6.4 inches) | 84% | high |
| November Weather | 2°C (37°F) | 105 mm (4.1 inches) | 89% | moderate |
| December Weather | -2°C (29°F) | 100 mm (4.0 inches) | 86% | low |