Weather in Dallas in September

Shoulder season. September is shoulder season in Dallas — cheaper, quieter, and a genuine gamble. Highs average 32.4 °C, lows 20.5 °C, and rain falls on 8 days — nothing in the month is working against you.

September ranks 9 of 12 in Dallas: past the worst of the year but short of November, which is the month to book if the dates are open.

Rain on 8 days, 2 of them heavy. Enough to need a plan B, not enough to need a plan around it. Pack for 32.4 °C days and 20.5 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 8 days clear 35 °C, so a serious heatwave is normal rather than notable. Across the twenty years measured, the hottest September day reached 42.7 °C and the coldest night fell to 10.5 °C, and the wettest single day dropped 84 mm — roughly 109% of the month's rain in one day.

September is moderately variable: 12 mm in the driest year against 202 mm in the wettest, around an average of 77 mm. Roughly two Septembers in three land near that average, and the third does something else entirely.

Wind is light at 9 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 63%.

How September sits in the year

The month is on the way down: 4.1 °C cooler than August, with October dropping another 5.9 °C. The first week and the last are not the same trip.

Daylight in September

12.4 hours of daylight, losing 1 hours across the month. That is between Dallas's extremes of 14.3 and 10 hours, so days are long enough not to constrain the plan.

An inland climate

With no coast nearby, the year swings a fair way — 35.1 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.

How busy it gets

Quiet. Few other visitors, cheaper rooms, and a real chance some seasonal operators are shut.

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

September in Dallas versus nearby

If Dallas is one option among several, the nearby comparison is worth making. Shreveport is close enough to be a coin toss — within a degree on temperature, 1 day more rain. Oklahoma City is a better bet in September — 2.7 °C cooler, 1 day more rain.

So: September is a compromise. November is 27 points better and is what Dallas is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Dallas

See all twelve months in Dallas, or where else to go in September.