Weather in Philadelphia in October

Prime time. If you get to pick your dates, October is the one. Highs average 19.5 °C, lows 8.6 °C, and rain falls on 9 days — nothing in the month is working against you.

October ranks 2 of 12 in Philadelphia. Only September scores clearly higher, and the difference is small enough to be settled by price rather than weather.

Rain on 9 days, 4 of them heavy. Enough to need a plan B, not enough to need a plan around it. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

Averages flatten a month, and this one hides a few things: it never really gets hot: not one day in an average October reaches 30 °C. Across the twenty years measured, the hottest October day reached 35 °C and the coldest night fell to -3.7 °C, and the wettest single day dropped 80 mm — roughly 73% of the month's rain in one day.

October is moderately variable: 24 mm in the driest year against 252 mm in the wettest, around an average of 110 mm. Roughly two Octobers in three land near that average, and the third does something else entirely.

Wind is light at 6.6 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 78%, high enough to notice on the warm days without dominating them.

How October sits in the year

The month is on the way down: 7 °C cooler than September, with November dropping another 6.6 °C. The first week and the last are not the same trip.

Daylight in October

11.2 hours of daylight, losing 1.3 hours across the month. That is between Philadelphia's extremes of 15 and 9.4 hours, so days are long enough not to constrain the plan.

An inland climate

With no coast nearby, the year swings a fair way — 34.9 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

October in Philadelphia versus nearby

If Philadelphia is one option among several, the nearby comparison is worth making. New York City is close enough to be a coin toss — within a degree on temperature, 1 day more rain. Washington is close enough to be a coin toss — within a degree on temperature, the same number of rain days.

So: October is effectively as good as it gets here — 3 points behind September, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Philadelphia

See all twelve months in Philadelphia, or where else to go in October.