As of 11:54 AM EDT on March 23, 2026, out of 15 cities in Franklin County, PA in our database, 11 cities (73%) have a UV Index reading of Low, while 4 cities (27%) have a UV Index reading of Moderate. The city with the highest UV Index reading right now is Greencastle, PA with a reading of 3.5.
Over the next 24 hours, the highest UV Index reading in Franklin County, PA is expected to be 5.6 in Mercersburg between 1:00 PM - 2:00 PM EDT today.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |