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How Wet Has 2024 Been?

June 1, 2024 – On the first day of what experts predict will be a record-setting 2024 hurricane season, I thought it would be interesting to see how much rainfall we had in May and so far this year. How wet has 2024 been?

May 2024 rainfall caused the second highest release from Lake Conroe in the history of the San Jacinto River Authority. But whether May 2024 will go into the records books depends on where you live.

Huntsville smashed its record high precipitation total for the month and year to date (YTD).

Conroe also set a record for May, but its YTD total fell slightly behind the record set in 1935.

Bush and Galveston came close to their record high totals for May and YTD.

At all four reporting stations that I sampled, YTD rainfall was well above normal.

However, the National Weather Service showed dramatic differences between locations.

More Than 5X Difference Across Region

According to the National Weather Service, Huntsville had the rainiest May since record keeping began – 24.7 inches. That brought Huntsville’s total for the first five months to 58.97 inches – about 10 inches higher than the average rainfall for an entire year.

58.97 inches is also almost triple the normal year-to-date (YTD) total for Huntsville.

At other reporting stations during the last 25 years:

  • Conroe had its rainiest May – 12.58 inches
  • Bush Intercontinental Airport had the fifth rainiest May – 11.05 inches.
  • Galveston had its fourth rainiest May. But it was only 4.39 inches.

Huntsville received more than five times the rainfall in Galveston during May. That shows how high the rainfall was in the northern part of the San Jacinto River Basin.*

These statistics demonstrate three things:

  • May was very wet.
  • 2024 has been very wet so far.
  • Rainfall across the region has varied dramatically.

Conroe, Bush Intercontinental and Galveston did not set records for May. But their monthly totals all fell into the top quintile of the last 25 years. And that helped bring YTD totals to near record highs at all sampled locations.

See graphs below arranged geographically from north to south. The boxes superimposed over the graphs show the years of the record high and low totals for YTD precipitation as well as the precipitation in a normal year.

Note: Record year at this location so green and blue lines coincide.

2024 YTD Totals Compared to Normal YTD

When comparing normal YTD totals to 2024’s, we can see that:

  • Huntsville is 193% ahead of normal.
  • Conroe is 73% ahead.
  • Bush Intercontinental Airport is 51% ahead.
  • Galveston is 58% ahead.

2X Differences in Lake Houston Area

Rainfall can vary dramatically within much smaller areas than the Houston region. Take the Lake Houston Area, for instance. According to the Harris County Flood Warning System, during May 2024, the gage at:

  • US59 and the West Fork received 13.76 inches of rainfall.
  • West Lake Houston Parkway and the West Fork received 16.56 inches.
  • FM1960 bridge across Lake Houston received 12.28 inches.
  • Slightly upstream, FM1485 and the East Fork received 22.8 inches.

That meant an almost 2X difference between the high at FM1485 and the low at FM1960. The two locations are just nine miles apart.

80% of Annual Rainfall in First 5 Months

I live just two miles from the gage at the West Lake Houston Parkway bridge and recorded an almost identical amount of rainfall in my back yard.

My gage received 16.45 inches for the month. That was just a tenth of an inch less than the Harris County Flood Control gage at WLHP.

And that brought my total rainfall for the year to 40.12 inches. Our average annual rainfall is only 50 inches. So we’re already at 80% of a normal year. I received a third of an average year in the month of May alone.

So, it was a very wet month for the Rehak household, even though we received 8 inches less than Huntsville’s mind-boggling 24 inches.

Today, another hurricane season starts. All early predictions indicate it could be a record-setting season. So keep those umbrellas handy.

Posted by Bob Rehak on June 1, 2024

2468 days since Hurricane Harvey

* Footnote: The NWS charts below all show monthly rainfall for the last 25 years. I have sorted the years in descending order based on May rainfall totals and highlighted where 2024 ranks for each reporting station.