National Weather Service Forecast for: Lancaster, OH Issued by: National Weather Service Wilmington, OH

Updated: 4:00 pm EDT Sep 29, 2026

This Afternoon Sunny Wednesday Patchy Fog then Partly Sunny Thursday Mostly Sunny Friday Showers And T-Storms Saturday Slight Chance Rain Showers then Partly Sunny Sunday Chance Rain Showers Monday Sunny   Hi 77 °F Hi 79 °F Hi 83 °F Hi 77 °F Hi 67 °F Hi 69 °F Hi 64 °F     Tonight Mostly Clear Wednesday Night Mostly Cloudy Thursday Night Mostly Cloudy Friday Night Showers And T-Storms Saturday Night Chance Rain Showers Sunday Night Slight Chance Rain Showers then Partly Cloudy Monday Night Mostly Clear   Lo 55 °F Lo 63 °F Lo 67 °F Lo 52 °F Lo 51 °F Lo 46 °F Lo 41 °F

Forecast from NOAA-NWS for Lancaster, OH.

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FXUS61 KILN 291640
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
1240 PM EDT Tue Sep 29 2026

.WHAT HAS CHANGED...
No significant changes.

&&

.KEY MESSAGES...
1) A gradual warming trend is expected this week, with rain chances
returning Friday into early Saturday.

2) Cooler and drier conditions will return Sunday into early next
week.

&&

.DISCUSSION...
Key Message 1)
Sfc high pressure will gradually shift E of the OH Vly through
tonight, allowing for warmer air to advect northward on the wrn
periphery of the departing high. Slightly higher PWs will also evolve
into the region midweek as deep-layer SW flow gradually increases.
Both overnight and daytime temperatures will continue to nudge upward
through Thursday, with highs reaching into the lower to mid 80s
Wednesday and upper 80s to near 90 degrees on Thursday.

Although conditions may not be /quite/ as favorable tonight as has
been the case the past several nights, patchy to areas of river
valley fog should again develop, particularly along the larger
waterways. Some patchy fog can also be expected in parts of central
to south-central OH where the skies will remain the clearest and wind
will be the calmest.

Midlevel ridging will expand across the OH/TN Vlys Wednesday into
Thursday before dampening with the approach of a trof by Friday.
Mid/high level clouds will begin to overspread the region through
this time well ahead of any rain chances. The trof will flatten with
eastward extent, becoming less pronounced into late Friday and
Friday night. Even so, expect a band of light rain to overspread the
area by Friday afternoon into Friday night from NW to SE, coincident
with the frontal passage. Friday may end up being a somewhat soggy
day across most of the area, even with relatively modest rain amounts
(generally one quarter to one half inch). With this, highs on Friday
will be substantially cooler than will be the case Thursday, with
the drier and cooler air filtering in by Saturday into Sunday.

There are still some uncertainties regarding the development of a
weak wave along the front Saturday, which may cause the front to slow
its southward progression or perhaps stall, potentially allowing the
rain to linger a bit longer across far S/SE parts of the local area.
Should this scenario evolve, rain may linger near/south of the OH
Rvr into Saturday/Saturday night as well. However, confidence remains
high in a return to drier conditions for most, if not all, of the
ILN FA by Saturday afternoon through the remainder of the weekend.

Key Message 2)
Confidence is high in a return to dry conditions by early next week,
with below normal temperatures likely Sunday through Tuesday.
Depending on the exact setup, some very patchy frost cannot be
completely ruled out Sunday night and especially Monday night, but
confidence in this scenario is low at this juncture. Ensemble probs
of temps at or below 38F are about 10-20% Monday night, particularly
near/north of I-70.

&&

.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
Aside from a few cirrus and perhaps a few VFR Cu this afternoon,
skies will remain generally clear through tonight. Cirrus will
overspread the region late in the night into the daytime Wednesday.

River valley fog is expected to develop yet again tonight, resulting
in additional vsby reductions at KLUK. Elsewhere, VFR conditions are
forecast to prevail.

Winds will remain very light out of the SE through tonight before
veering more toward the SSW on Wednesday. Winds will increase to
about 10kts by late in the period.

OUTLOOK...MVFR/IFR conditions are possible Thursday night into
Friday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.

&&

$$

DISCUSSION...KC
AVIATION...KC

NWS ILN Office Area Forecast Discussion