On 20 August 2023 the daily maximum gust modelled at Irvine was about 46 mph, which falls in the strong band below the 58 mph severe threshold, but it is well into the range that finds anything already loose on a roof.
How strong was the wind on 20 August 2023
According to the Open-Meteo ERA5 reanalysis archive, the daily maximum 10 m wind gust modelled at Irvine on 20 August 2023 was about 46 mph. That sits in the strong band, under the 58 mph line that marks severe wind in this record, but still strong enough to matter to a roof that has any weak points already.
The 46 mph figure is a single daily maximum, not an hourly average, so it describes the peak of the gust that day rather than how long it blew. A gust that size passing over a neighborhood for even a short stretch is enough to move a shingle edge or a flashing strip that was already working loose before the storm arrived.
What does 46 mph actually do to a roof
A gust in the strong band, below 58 mph severe, does not typically strip sound roofing outright. What it does is act as a test of anything marginal: a shingle tab with failed adhesive, a ridge cap with a popped nail, a piece of flashing that was never fully sealed. Those are the parts of a roof that move first when the wind picks up, well before the structure itself is at any real risk.
Because the threshold for severe wind in this record is 58 mph, a day measured at 46 mph is a reminder that damage does not require a headline storm. It requires an existing weakness and enough gust to exploit it. A roof in good repair going into a 46 mph day usually comes out the same way it went in.
Is this gust figure a measurement from the street
No. Gust figures here are ERA5 reanalysis at the city location, not a reading from a mast in the street. The 46 mph number is a modelled value for the Irvine location on that date, built from a reanalysis dataset rather than a local weather station reading at a specific address.
That distinction matters for how the number should be used. It is good for comparing days against each other and for knowing which storms were worth checking after, not for pinning down what a single property on a single block actually experienced. Two homes a mile apart could see somewhat different real gusts even on a day with one modelled citywide figure.
What is worth checking after a day like this
According to the storm record for Irvine, 20 August 2023 sits among the days worth checking against for anyone trying to date when a roof problem started. If a leak or a loose shingle shows up months later, matching it to a dated gust event like this one gives a more useful timeline than guessing.
The practical step after a strong-band day is a visual check of ridge caps, flashing edges, and any shingle tabs near roof edges and valleys, since those are the points a 46 mph gust is most likely to have moved. A reader who finds something loose can submit a request through this site, which puts it in front of local contractors covering the Irvine ZIP code, automatically and in under 60 seconds, with no more than 3 able to take it on.