Washington County (Johnson City)
September
Weather in Washington County, Tennessee for September 2026
Your guide to Washington County weather in September - trends and predictions
So far, September 2026 in Washington County shows a warmer trend than usual by 3.8 °F.
The forecast for the next days in Washington County predicts temperatures to be around 21 °F, close to the historical average.
In general, the average temperature in Washington County at the beginning of September is 28.6 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 19.9 °F by the end of September.
Washington County experiences moderate rainfall in September, with an average of 9 rainy days and a total precipitation of 96 mm.
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Temperatures
Rain 🌧️
More
21
Dry days
9
Rainy days
0
Snow days
24°/14°
Temperatures
9 km/h
Avg max wind
77 %
Avg humidity
Washington County Weather September
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Temperatures trend during September in Washington County
See the weather trend as well as the moving average line
September weather in Washington County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Overcast | 29° /17° | 0 mm | 8 | |
| Sept. 2 | Overcast | 29° /16° | 0 mm | 8 | |
| Sept. 3 | Overcast | 29° /16° | 0 mm | 8 | |
| Sept. 4 |  Light rain shower | 31° /17° | 6.3 mm | 8 | |
| Sept. 5 |  Moderate or heavy rain shower | 31° /18° | 6 mm | 8 | |
| Sept. 6 | Light rain shower | 27° /18° | 6.4 mm | 7 | |
| Sept. 7 |  Light rain | 24° /16° | 3.3 mm | 6 | |
| Sept. 8 |  Sunny | 26° /11° | 0 mm | 8 | |
| Sept. 9 | Sunny | 27° /14° | 0 mm | 8 | |
| Sept. 10 |  Partly cloudy | 25° /13° | 0 mm | 8 | |
| Sept. 11 |  Fog | 27° /14° | 0.1 mm | 7 | |
| Sept. 12 | Partly cloudy | 26° /15° | 36.2 mm | 4 | |
| Sept. 13 | Fog | 25° /14° | 1.1 mm | 5 | |
| Sept. 14 | Mist | 25° /16° | 0.1 mm | 6 | |
| Sept. 15 |  Cloudy | 26° /16° | 0 mm | 7 | |
| Sept. 16 | Mist | 23° /15° | 0.1 mm | 6 | |
| Sept. 17 | Cloudy | 26° /16° | 0.4 mm | 7 | |
| Sept. 18 | Mist | 26° /17° | 2.4 mm | 6 | |
| Sept. 19 | Partly cloudy | 29° /15° | 0 mm | 7 | |
| Sept. 20 | Patchy rain possible | 25° /18° | 10.2 mm | 7.6 | |
| Sept. 21 | Patchy rain possible | 27° /20° | 5 mm | 7.4 | |
| Sept. 22 | Light rain shower | 23° /18° | 8.1 mm | 5.8 | |
| Sept. 23 | Patchy rain possible | 21° /13° | 15.8 mm | 5.8 | |
| Sept. 24 | Patchy rain possible | 21° /12° | 9.8 mm | 5 | |
| Sept. 25 | Mist | 20° /15° | 0 mm | 5 | |
| Sept. 26 | Light rain shower | 17° /12° | 16.3 mm | 4 | |
| Sept. 27 | Sunny | 21° /13° | 0 mm | 6 | |
| Sept. 28 | Sunny | 21° /13° | 0 mm | 5 | |
| Sept. 29 | Light rain shower | 17° /9° | 7.2 mm | 3 | |
| Sept. 30 | Mist | 22° /10° | 0.3 mm | 6 | |
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Important Notice
Our weather forecast for Washington County in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Washington County forecast closer to your planned date for the most up-to-date weather information.
Change Month
Washington County in September - FAQ
What are the expected maximum and minimum temperatures in Washington County during September?
Enjoy moderate daytime temperatures of up to 24° and cooler nights around 14°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Washington County during September?
Moderate rainfall is anticipated in Washington County during September, with a total of 96 mm spread over approximately 9 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Washington County during September?
The average wind speed in Washington County during September is 9 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Washington County
Explore the daily rainfall trends and prepare for Washington Countys September weather 💧
Typically, Washington County has 9 rainy days in September with a total of 96 mm of rainfall.
UV exposure in Washington County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is Washington County?Get accurate weather forecasts for Washington County, located at latitude 36.313 and longitude -82.353. Stay updated with localized weather information tailored for Washington County.
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