Hey all,
So I’m trying to settle a question. A friend of mine insists that Portland MUST have had at least one night recently when the temperature dropped below freezing. I say no. For one thing, the Weather Channel says not. (This doesn’t guarantee anything, though…) For another, my coleus is still happy, and I’ve lost many of them after about five seconds of frost. We “should” have had the first frost exactly a month ago, but I just don’t think it’s happened yet. We live close to each other, and we’re both in a very close-in suburb. Is there any way to settle this? How can we find out what the lowest temperature has been so far this fall? Is there a list somewhere of day by day lowest temps? Thanks in advance…
I’m guessing you aren’t in Portland, Maine.
The lowest temperature here will be tonight, about ten degrees. western Massachusetts. It’s been in the low twenties this week; this morning at dawn it was 19 degrees.
Weather Underground USED to be a good place to dump out multiple days of weather info but has gone through great lengths to limit that.
I don’t see a way on that site of finding the lowest temperature without scanning individual days.
The link I posted above can be used to dump out any time series you want.
Use the map tool to navigate to any weather station.
Place it in your cart (there is no fee for checking out your cart)
When you navigate to the cart you can specify a date range.
I usually dump it to a CSV file, wait a few minutes for the download link to hit my email, download and then read it into an excel sheet.
From there you can use Excel to determine the MX/Min/Whatever for the drybulb temperature.
The Summary section lists Max, Min and Average.
https://www.wunderground.com/history/monthly/us/or/portland/KPDX/date/2018-11
So there you go, but here’s a second link showing data from the nearest NOAA RAWS weather station in Eagle Creek (SE Portland fringes). In case you’re closer to that station.
https://wrcc.dri.edu/cgi-bin/rawMAIN.pl?orOEAG
- Select “Daily Summary Time Series” at left.
- Input desired date range.
- Select “Air Temperature” element (only).
Try National Weather Service - NWS Portland
If it’s the wrong Portland, the local NWS site should have about the same plots.
Maybe November 9?
Thanks all! 
So here’s what I found out: on November 9, the temperature dipped TO 32 degrees, but not BELOW it. So technically, I think you could say that it didn’t go “below freezing.” :rolleyes: It can’t have happened for more than an extremely short time, though, because my coleus are still doing fine right now. I’ve had them die on me before from literally half an hour of frost. Of course, it still doesn’t explain the mystery of why my friend (who lives maybe a mile from me) had her coleus die. Maybe a microclimate??
The air temperature is not taken at ground level, it is taken 5 feet above it. It is possible to have a decent frost on the ground without the temperature going below freezing.