Freeze-thaw days near Hammond, 2001 to 2025
In brief: NOAA records for Chicago Midway Airport, the nearest long-record station to Hammond, show an average of 59.4 freeze-thaw days a year from 2001 to 2025, from 45 to 87, nearly all between November and April[1].
What does this dataset measure?
A freeze-thaw day is counted here when the daily high is above 32°F and the daily low is below 32°F, so water on and in the glass both melts and freezes within the same day. The counts come from daily maximum and minimum temperatures at Chicago Midway Airport (NOAA station USW00014819), a long-record NOAA station on Chicago’s southwest side, the closest such station to Hammond with complete daily data for the period, in NOAA’s Global Historical Climatology Network daily (GHCNd)[1][2][3]. The period is 2001 to 2025, every month complete. The file also counts days with a low at or below 0°F.
How many freeze-thaw days does the area get?
Over the 25 years, Midway averaged 59.4 freeze-thaw days a year[1]. The most was 87 in 2018 and the fewest 45 in 2009. The 13 years from 2013 to 2025 averaged 59.5, against 59.3 for the 12 years from 2001 to 2012, so there is no clear trend in either direction over the period. Days at or below 0°F averaged 3.2 a year, with a high of 13 in 2014.
Which months are worst?
| Month | Average days | Most in one year |
|---|---|---|
| October | 0.4 | 2 |
| November | 8.3 | 15 |
| December | 11.8 | 21 |
| January | 11.6 | 20 |
| February | 12.2 | 18 |
| March | 12.4 | 20 |
| April | 2.6 | 11 |
| May | 0.0 | 1 |
March is the peak month, narrowly ahead of February, December and January; each averages about 12 freeze-thaw days. November averages about 8 and April about 3. From May to September there are essentially none[1].
What did each year look like?
| Year | Freeze-thaw days | Days ≤ 0°F |
|---|---|---|
| 2001 | 55 | 1 |
| 2002 | 72 | 1 |
| 2003 | 58 | 2 |
| 2004 | 53 | 4 |
| 2005 | 57 | 2 |
| 2006 | 68 | 1 |
| 2007 | 62 | 6 |
| 2008 | 71 | 9 |
| 2009 | 45 | 2 |
| 2010 | 48 | 0 |
| 2011 | 57 | 3 |
| 2012 | 66 | 0 |
| 2013 | 72 | 2 |
| 2014 | 52 | 13 |
| 2015 | 49 | 5 |
| 2016 | 55 | 3 |
| 2017 | 48 | 2 |
| 2018 | 87 | 4 |
| 2019 | 71 | 7 |
| 2020 | 72 | 1 |
| 2021 | 60 | 2 |
| 2022 | 57 | 4 |
| 2023 | 57 | 0 |
| 2024 | 46 | 3 |
| 2025 | 48 | 3 |
Why does this matter for a windshield?
A small chip or crack lets water into the glass. When that water freezes it expands, and repeated freezing and thawing can lengthen a crack. Daily swings also mean drivers often run the defroster on a cold windshield, which heats the glass unevenly. Industry repair standards say damage should be repaired before contamination enters it, and that cracks longer than set limits should be replaced instead[4]. In the Hammond area, the long run of freeze-thaw days from November to April is the season when a chip is most likely to spread. See winter windshield damage.
How was it built?
- Downloaded the GHCNd daily file for USW00014819 from NOAA NCEI[2].
- Kept days with both TMAX and TMIN, converted from tenths of a degree Celsius to Fahrenheit.
- Counted freeze-thaw days (TMAX above 32°F and TMIN below 32°F) and days with TMIN at or below 0°F by month.
- Checked that every month from 2001 to 2025 had full data.
- Published the results as a CSV file under CC BY 4.0.
Midway is in Chicago, not Hammond, and conditions near the lake can differ by a few degrees. The counts describe air temperature, not glass temperature, which also depends on sun, wind and the car’s heater.
Questions and answers
How many freeze-thaw days does the Hammond area get?
About 59 a year at nearby Chicago Midway Airport, 2001 to 2025.
Which month has the most freeze-thaw days near Hammond?
March, narrowly, with about 12; December, January and February are close behind.
Can I download the data?
Yes, as a CSV file linked on this page.
Related articles
Notes
- ^ a b c d Global Historical Climatology Network daily (GHCNd), station USW00014819, Chicago Midway Airport. NOAA National Centers for Environmental Information. Checked 9 November 2026.
- ^ a b Global Historical Climatology Network daily (GHCNd). NOAA National Centers for Environmental Information. Checked 9 November 2026.
- ^ Chicago Midway International Airport. Wikipedia. Checked 9 November 2026.
- ^ The Right Repairs at the Right Time (ROLAGS repair limits). National Windshield Repair Division. Checked 9 November 2026.