Corydon, IN Weather

Key Messages

* River valley fog is possible tonight, with isolated areas of dense river valley fog possible.

* Patchy frost will be possible early Friday and Saturday mornings, mainly in sheltered rural areas.

* Dry weather and consistent temperatures are expected through next Wednesday.

Discussion

Issued at 344 PM EDT Thu Oct 22 2026

Its another beautiful day across southern Indiana and central Kentucky, with current temperatures in the upper 60s/low 70s and mostly clear skies. A broad area of surface high pressure extends off to our north, as well as a sturdy upper-level ridge that is centered over the central CONUS. Northwesterly flow aloft continues to persist, allowing dry air to remain in place. Daytime mixing has allowed RH values to drop into the lower 30% range, with some places getting into the 20s. This trend will continue through at least the end of the workweek while northwesterly flow remains. While we are able to mix out well during the daytime hours, decent radiational cooling will allow overnight temperatures to drop to near or below normal for this time of year. Lows in the upper 30s to low 40s are forecast tonight, allowing for patchy frost to develop in low-lying rural areas. Additionally, there will be the potential for fog to develop tonight, though the persistence of dry air over the region should keep this confined to river valleys most prone to fog development.

This stretch of wonderful weather will continue through the weekend and into next week as the broad area of surface high pressure persists over the region. The area of surface high pressure will further build this weekend, extending to the south and east as it does so. Meanwhile, the upper-level ridge will slowly shift eastward over time, with the axis of the ridge moving over the region by early next week. While there may be some subtle wind direction shifts as these features shift, the overall forecast remains fairly consistent across the region. Highs through the end of the forecast period will be in the 70s, with lows in the upper 30s/low 40s through Saturday, and broadly in the 40s through next Thursday.

Our next chance for appreciable rainfall still remains uncertain, with some spread in solutions showing up in deterministic and ensemble guidance. Models are picking up on a weak front moving through the Ohio Valley during the middle parts of next week, though the antecedent dry air over the region could limit the potential for rain. LREF guidance only shows a 10-15% chance for rain during the Wednesday-Thursday timeframe, so chances are likely low with that feature. Chances do increase some (20-30%) beyond the end of the forecast period on Halloween, but the uncertainty in model guidance right now does not give much confidence in highlighting a solid potential for decent rainfall.

Aviation

Issued at 151 PM EDT Thu Oct 22 2026

VFR conditions are expected to prevail through the TAF period. Winds this afternoon will be out of the NNE at 5-10 kt, diminishing after sunset. Winds will shift to more of an easterly direction Thursday night, with speeds getting up to around 7 kt by the end of the TAF period. Patchy valley fog is possible tonight, though confidence was too low to include in any of the TAFs.

Lmk Watches

KY...None. IN...None.