Frost history / Natrona Lock 4, PA
Natrona Lock 4, PA: frost dates by year
Last spring and first fall frost at NOAA station USC00366151, 2011 to 2025, measured from daily minimum temperatures.
Elevation 760 ft, 40.614, -79.719. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Apr 25 | Oct 29 |
| Earliest | Apr 1 (2011) | Oct 17 (2020) |
| Latest | May 10 (2020) | Nov 17 (2022) |
| Trend | 10.9 days later per decade | 3.5 days earlier per decade |
| Years with data | 13 | 14 |
At 28°F (hard freeze) the median last spring date is Apr 4 and the median first fall date is Nov 12.
The trend is a straight-line fit through the years with a freeze. A positive spring trend means the last frost now comes later. Short or patchy records give noisy trends.
Chart
Last spring frost (32°F)
First fall frost (32°F)
Dots are single years. The gray line is the median, the green line the fitted trend.
Year by year
| Year | Last spring 32°F | First fall 32°F | Last spring 28°F | First fall 28°F |
|---|---|---|---|---|
| 2025 | no data | Oct 17 | no data | Nov 14 |
| 2024 | Apr 23 | Oct 27 | Mar 25 | Dec 1 |
| 2023 | Apr 26 | Oct 23 | Apr 9 | Nov 2 |
| 2022 | Apr 29 | Nov 17 | Apr 21 | Nov 19 |
| 2021 | Apr 27 | Nov 4 | Apr 4 | Nov 5 |
| 2020 | May 10 | Oct 17 | Mar 9 | Nov 14 |
| 2019 | Apr 4 | Nov 2 | Apr 4 | Nov 8 |
| 2018 | Apr 22 | Oct 26 | Apr 22 | Nov 11 |
| 2017 | May 9 | Nov 8 | Mar 24 | Nov 8 |
| 2016 | Apr 14 | Oct 26 | Apr 11 | Nov 12 |
| 2015 | Apr 25 | Oct 19 | Apr 2 | Nov 23 |
| 2014 | Apr 25 | Nov 3 | Apr 17 | Nov 14 |
| 2013 | Apr 22 | Nov 4 | Apr 7 | Nov 4 |
| 2011 | Apr 1 | Oct 30 | Apr 1 | Nov 5 |
"none" means the station recorded no freeze at that threshold in that half of the year. "no data" means more than 10% of the season's daily readings were missing. Years with no usable data are left out. See the methodology for the rules, and the ZIP lookup for 1991 to 2020 frost probabilities.