Record rainfall in a continental U.S. state in one month?

Hey all,

I’m trying to find out what the all-time monthly record rainfall is for a continental U.S. state.

This seems like it should be an easy question to answer, but I am not having any luck at all. The problem is that every list I’ve found puts the same state at the top… Hawaii. Here’s a good example:

107 inches in March 1942 in Kukui, Maui, Hawaii. But what about one of the lower 48 states??

Yep, there is actually a point to this… it looks like Oregon will easily break its record one-month rainfall, so I’m trying to find out how far we’d have to go for the alltime record anywhere. Obviously, we aren’t going to break the Hawaii record, so the next best thing would be one of the 48 states. :rolleyes: But it’s really weird how difficult it’s been to find that info. Does anyone know? All ideas appreciated…

I can’t provide you with much help, but you are mixing your terms up a bit.

Continental US includes Alaska (because it is on the continent).

Contiguous US states are the lower 48, because they touch each other.

It sounds like you do not want to include Alaska since you mention the lower 48.

This is not an easy thing to google, it appears that monthly rainfall is not a popular metric.

You might want to try asking your local TV meteorologist via email or twitter. Generally meteorologists welcome questions from the public and have better resources available to look up the records.

In terms of rainfall amount, the Pacific Northwest actually isn’t that wet. (In terms of days of rain per year on the other hand…) The rainiest states by amount are the gulf coast states because, while they don’t get the constant drizzle like the PNW, they get huge amounts of rain during tropical storms. I’d guess that the rainiest month would be in one of those states during a big storm, and that it’s way more than whatever cute little record you’ve set out in arid Oregon.

Actually, googling I see the Oregon record in question is 13.35 inches, which is 339 mm. If you look at your own link you see that Alvin, Texas got 1029 mm in 24 hours!

Here’s a list of states ranked by average annual rainfall. Oregon isn’t anywhere near the top, being 36th. Although the coast is very rainy, the inland areas are dry.

The rainiest state in the continental US is Louisiana, with 60.1 inches. Mobile, Alabama, is the rainiest city, with 67 inches.

The highest annual rainfall in New Orleans was 85.73 inches, which occurred in 1927, the year of the Great Mississippi Flood. I haven’t located figures for Louisiana as a whole for that year, but I suspect the maximum for a state would probably be Louisiana or Mississippi in 1926 or 1927.

Average rainfall and one-month record rainfall are not necessarily correlated.

Actually, they probably are correlated to a considerable degree, although the state with the highest average and highest one-month record may not be the same. In any case, the figures suggest that some state other than Oregon is likely to have the highest monthly total, and that state is likely to be on the Gulf coast.

The problem is that figures are generally given for average annual rainfall by state, but monthly rainfall by city. It appears rare to give summary figures by month for states.