Topic: Very strange one-time temperature spike from 5-in-1 and Access:

[BeaverMeadow]

I was looking at my wu graph yesterday and saw a temp spike in the morning of 107 degF. It was also on the MyAcurite graph. I d/l'd the table data from Acurite to confirm:

5-in-1 Weather Station   5-in-1 Weather Station   2019/04/15 10:00 AM   56.8
5-in-1 Weather Station   5-in-1 Weather Station   2019/04/15 10:05 AM   56.7
5-in-1 Weather Station   5-in-1 Weather Station   2019/04/15 10:10 AM   56.3
5-in-1 Weather Station   5-in-1 Weather Station   2019/04/15 10:15 AM   56.7
5-in-1 Weather Station   5-in-1 Weather Station   2019/04/15 10:20 AM   107.5
5-in-1 Weather Station   5-in-1 Weather Station   2019/04/15 10:25 AM   56.5
5-in-1 Weather Station   5-in-1 Weather Station   2019/04/15 10:30 AM   56.5

Has this ever happened to anyone else? What could be the cause? Definitely not the fan-- it was a morning with lots of clouds and and alternating sun for several hours so there would have been multiple spikes. Fan works perfectly. Even if the fan for some reason got hung up for a minute I can't imagine a 50 deg spike occurring within a 5 minute time window.

I have one theory but it is pretty far fetched-- I wonder if anyone will come up with the same one?

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[Sir_MAK]

Is the other line the Dew Point?  It doesn't show the increase.

[BeaverMeadow]

Is the other line the Dew Point?  It doesn't show the increase.

It doesn't show dew point spike on WU but it does on MyAcurite--

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[awsum140]

I used to have spikes like that happen when I used a "hub".  I traced it out to a conflict, of sorts, on the USB buss with that one.  This is the first time I've heard/seen it happen with an Access device though and the Access is a direct internet connection, too boot.  I suppose it could have been data corruption somewhere between the 5N1 and AcuRite, but that is pure speculation.  Really odd that AcuRite showed a corresponding dew point spike while WU didn't.  Maybe contact AcuRite, although their help responses are usually too generalized/vague to be really helpful.

[davefr]

Large temperature spikes can be the result of the SHT21 temperature sensor daughter board starting to going bad. It's easy and cheap to repair/replace.  How old is your 5 in 1 and are you in a salt air environment?

https://www.wxforum.net/index.php?topic=35467.msg363408#msg363408

[BeaverMeadow]

Large temperature spikes can be the result of the SHT21 temperature sensor daughter board starting to going bad. It's easy and cheap to repair/replace.  How old is your 5 in 1 and are you in a salt air environment?

https://www.wxforum.net/index.php?topic=35467.msg363408#msg363408

It's two years young and the first time I have had a spike like that for no discernible reason. I hope it's not a failing board but if I start getting more spikes like that I will look into your suggestion.

I've heard of forest fires starting from tree leaves acting as a lens and focusing a concentrated beam of light on some forest floor kindling. It crossed my mind that somehow a similar concentrated beam hit the pws but that would only make sense if the temp sensor was exposed and not internal to the unit. So that couldn't have been it.