Eric Berger

In brief: After a pair of almost fall-like weather days, Houston’s pattern will tilt back toward summer. As high pressure asserts control our forecast looks to be locked in for pretty much the next 10 days: hot days, lots of sunshine, and virtually no chance of rain.

High pressure in September

When it comes to weather, most people understand that low pressure equates to the potential for stormy conditions, whereas high pressure creates a more stable atmosphere with sinking air. At most times of year when we see high pressure (sinking air) this leads to mostly sunny or cloudless days. This can feel fantastic in February or March, but decidedly sultry and hot in July and August.

By the middle of September we are starting to edge toward fall, with shorter days and a lower Sun angle, high pressure hits a little bit different. Instead of high temperatures of 100 degrees like in August, we are likely to see highs generally in the mid-90s. Instead of lows around 80 degrees, we are likely to see low- to mid-70s. Dewpoints should be 5 to 10 degrees lower which means the air will feel slightly less humid than peak summer.

So for those who want a little bit more summer, you’re in luck. For those pining for fall after the last couple of days, it’s going to be a loooong week, at least.

Wednesday

It is another pleasantly cool morning across the region, with the usual spots such as Conroe dipping into the upper 50s and much of Houston in the mid-60s this morning. Alas, all good things must end. Winds will turn easterly today, increasing an onshore flow, and starting to increase humidity levels. For the most part I think highs today will remain in the low- to mid-90s, with sunny skies. Lows tonight will only drop into the mid-70s, so about 10 degrees warmer for most locations. With light winds today, conditions are favorable for producing elevated levels of ozone. An Ozone Action Day is in effect.

Thursday through Sunday

Each of these days is going to be very, very similar. We can expect mostly sunny to cloudless days with highs in the low 90s near the coast and mid-90s for most of the rest of the area. Some far inland locations may push into the upper 90s. Most days will have modest southeasterly winds at about 10 mph. Nights will be in the mid-70s. Rain chances will be essentially zero. If you have outdoor plans our confidence in this forecast is very high.

Next week

Not much changes for at least the first half of next week: same skies, same temperatures, similar humidity. Rain chances are low through at least Wednesday or Thursday, by which time coastal areas may start to see some isolated showers. Really, I don’t see any real spark of change in this pattern until at least next weekend, and maybe not then.

Atlantic tropics

Today is the historical peak of the Atlantic hurricane season. Yet this year, there is precisely nothing to talk about. That is ideal!

In brief: It’s officially Fall Day in Houston, with the season’s first 65-degree temperature reading this morning. We are also excited to announce that we’ll be holding our Fall Day Celebration on October 25 in Houston. More details in today’s post, which discusses our largely unchanging weather for the next 10 days. We also talk tropics.

Fall Day celebration

The temperature at Houston’s official weather station, Bush Intercontinental Airport, fell to 65 degrees this morning (and it currently has reached 64, as of 6:20 am). That means we can officially declare today as “Fall Day” in Houston. If you’re unfamiliar with this little tradition, it’s simply the day when we get our first real taste of fall in the city after a long summer.

Speaking of this, I’m excited to announce that we are planning a special Fall Day Celebration for Saturday, October 25. This year’s event will also commemorate the 10th anniversary of Space City Weather. This year we are gathering at Midtown Park from 10 am to Noon. We will have more information soon, but rest assured we are planning a special event for you and your families. Come celebrate with us!

Tuesday

This deligtfully dry air will persist today and tonight before a more easterly flow starts to raise humidity. As a result we can expect sunny skies today, with high temperatures around 90 degrees. With dewpoints in the 50s, this afternoon will like Monday bring a somewhat dry heat into the area. This evening will be pleasant. Lows tonight will drop to around 70 degrees in Houston, with cooler conditions further inland.

Wednesday through the weekend

As high pressure builds from the west, I don’t expect much variability in our weather for the remainder of the week. Each day should bring sunny skies and high temperatures in the low 90s in Houston, with areas further inland (i.e. Katy and The Woodlands) likely pushing into the mid-90s. Dewpoints will be in the 60s, generally, so while the air will be more humid, it won’t be the super sticky humidity we see during summertime in Houston.

Lows will generally fall into the low- to mid-70s. Rain chances throughout this period will basically be zero, except for the immediate coast, which might see slightly higher chances (i.e. 10 or 20 percent) on some afternoons.

Next week

This pattern has to change at some point, right? Well, eventually. Mostly, however, I expect it to persist into at least the middle of next week. At that point rain chances may tick up slightly, but I don’t see any evidence of the next front at this time. So after today it will be late summertime weather for awhile.

Atlantic tropics

It’s very quiet there for what is typically the peak of the Atlantic hurricane season. We have zero concerns at this point. When we look out for the next 10 days, conditions look to be fairly quiet. The sub-seasonal forecast from the European model, shown above, predicts significantly less activity than normal in the Atlantic basin (40 percent of normal). By the last 10 days of the month this model is back to predicting near-normal activity in the Atlantic, and overall conditions should improve. But long-time readers of Space City Weather will know that our window for seeing a hurricane landfall in the greater Houston region is closing. I’m certainly not ready to declare the season “over” for Texas, but we are just weeks away from that happening. So we’re in the home stretch.

In brief: In today’s post we talk about the region’s flirtations with fall, and we are going to have a couple of very fine days with cooler nights. But after this a warmer and somewhat more humid pattern returns, although we are beyond the worst of summer. Dwight also checks in with an update on our app!

Fall’s first front

A decent front has pushed offshore, and we are seeing rather dry air move into the region. As as result humidity will feel decently low today and Tuesday. The big question for me is, will we hit 65 degrees tonight? It’s going to be close. That is our arbitrary definition of the first fall-like weather in the city. Since the city’s official station moved to Bush Intercontinental Airport in 1969, the average date of the first 65-degree (or cooler) night has been September 12, so we’re close to that time of year. Regardless, it will feel notably cooler tonight than we have experienced since May 12.

Final app update🤞🏻for 2025

(The following update comes from Dwight). As summer fades, so does our annual development push for the Space City Weather app. Over the past couple of months, developer Hussain Abbasi has been cranking away on updates for the Apple and Android versions, smashing bugs and tuning the apps for performance. We think both are in a good place right now, and pending any undiscovered issues, we’re happy. We hope you are, too!

And you appear to be, because over the past few weeks, the number of bug reports we’ve received have dwindled to near-nil. Thanks to everyone who used the Send Feedback button in the app to make those reports. They help!

And as part of our new Discourse platform, which handles blog comments in a forum setup, we have added a new category: App Feedback. Got comments, questions, concerns or feature requests? App Feedback is the place to leave them. In addition, we’ve got an initial post which serves as a mini FAQ about the SCW app, with a few Good Things to Know™ as well as instructions for filing a bug report. Please give it a read before posting in this new forum category, because there’s a good chance your question is already answered there.

As always, thanks for downloading and using the app!

Monday

Today will be sunny and warm, with a high temperature in the upper 80s to 90 degrees for the metro area, with a northeast wind of about 10 mph. I highly recommend planning to spend this evening outdoors because it is going to be lovely, with mild temperatures and drier air. Seriously, this is porch weather. I don’t have a great handle on how low temperatures will go tonight, but I think Houston will fall into the upper 60s, with inland areas dropping into the lower 60s to upper 50s.

Tuesday

This will be another day with reasonably dry air. Expect sunny skies and highs around 90 degrees. As winds shift to come from the east humdity will start to come up a little. Still, I expect Houston to see lows around 70 degrees with inland areas dropping into the 60s on Tuesday night.

Wednesday, Thursday, and Friday

We return to a more summer-like pattern for the rest of the week as high pressure starts to build. However since we’re now approaching mid-September, this means highs generally in the low- to mid-90s, with nights in the mid-70s. Dewpoints will be high, but not opppressively so. So hot, yes. But super hot, no (see, for example, the wet bulb globe temperatures in the graphic above). Expect sunny skies and no rain.

Saturday and Sunday

The weekend looks the same: Sunny skies, highs in the low- to mid-90s, with a fair but not exessive amount of humidity. Rain chances appear to be close to zero through the weekend.

Next week

This pattern of highs in the low- to mid-90s should persist into next week as late summer holds on. Some rain chances may finally return to the forecast about 10 days from now.

The Atlantic tropics

Things are surprisingly quiet right now for September, with zero threats in the Atlantic. We only have a few weeks left of “prime time” for storms in Texas. Tomorrow I’ll take a look at what may happen during that time.

In brief: The region will heat up today and Friday, with moderately drier air in place. A combination of factors, including a slow-moving front, will bring elevated rain chances this weekend, particularly on Sunday. Slightly cooler weather will follow.

Thursday

A close look at the radar reveals a few showers right along the coast this morning—that’s the stalled front that has brought modestly cooler weather into the Houston region this morning. Lows at Conroe have dropped all the way into the mid-60s, but most of the metro area has settled into the low 70s. Because this dry air warms efficiently, and skies will be sunny, we will see highs today in the mid- to upper-90s for much of the region away from the coast. With dewpoints in the 60s this afternoon it will be a slightly drier heat, but it’s still going to be pretty hot. Winds will be light, from the west at about 5 mph. Lows tonight will be a couple of degrees warmer than this morning.

Friday

This will be another sunny and warm day, with highs in the mid-90s for much of the area. However, winds will turn more southerly, with gusts up to 15 or 20 mph, and this will herald the return of the onshore flow. This is one factor that will lead to higher rain chances over the weekend, but only one. Friday night will see lows drop into the upper 70s.

Saturday

The first half of the weekend will see a few more clouds in the sky, but there should be enough sunshine to help push temperatures for most into the vicinity of 90 degrees, or just above. Rain chances are about 40 percent, but for the most part I think any showers that develop will be light to moderate, and not super impactful. With ample humidity in place, look for a warm Saturday night.

Sunday

Rain chances will peak on Sunday, likely in the 60 to 80 percent range. Why? Because the combination of a front dropping down from the north, along with an influx of moisture from the remnants of Hurricane Lorena in the Pacific, should bring a healthy chance of showers across the area. We certainly cannot rule out the threat of heavy rainfall, but at this time I expect most of the region to pick up between 0.25 and 1 inch of rain this weekend, rather than seeing any significant flooding. But we’ll keep an eye on it. Highs, for the most part, should top out in the upper 80s.

Next week

At this point it looks like the front will drag into Houston on Sunday-ish, and stall out near the coast. Depending on where the front stops, we could see some lingering showers next week for coastal areas, or they should remain offshosre. Regardless, we should see a couple of days in the upper 80s to 90 degrees, with nights in the lower 70s. Some inland areas may drop into the upper 60s again, so pretty nice overall. Most of next week should be sunny.

Tropics

A disturbance progressing across the Atlantic is increasingly likely to become a tropical storm, and then possibly a hurricane over the course of the next week. There remains a ton of uncertainty about where this will ultimately go, and since it is early September we need to keep an eye on its development. However, overall the odds of this system affecting Texas look to be quite low at this time.