Extreme Heatwaves in Maryland
1991-2020 Baseline Climatology: January 1 - December 31
Definition: Hot Day/Night: Daily Tmax & Tmin > 95th Percentile Thresholds | Heatwave: 3 or more consecutive Joint Hot Days/Nights.
Data Source: NOAA nClimGrid-Daily v1.0.0.
| Region | No. of Hot Days/Nights | Climatological No. of Hot Days/Nights | No. of Joint Hot Days/Nights | Mean Temp among all Joint Hot Days/Nigths | Maxium Temp among all Joint Hot Days/Nigths | Day when Max Temp among all Joint Hot Days occurred | No. of Heatwaves (#) | Mean Duration of Heatwaves (days) | Longest Heatwave (days) | Start of the First Heatwave | Start of Last Heatwave | Mean Temp of all Temps in Heatwaves | Mean Temp of Heatwaves' Mean Temps | Max Temp of Heatwaves' Mean Temps | Number of Heatwave when Max Temp of Heatwaves' Mean Temps occurred | Max Temp within all Heatwaves | Day when Max Temp within all Heatwaves occurred |
|---|
| Maryland Statewide | 19.8 / 19.7 | 19.8 / 19.7 | 9.4 | 81.1 / 59.2 | 100.7 / 77.6 | Jul 27 | 0.8 | 3.3 | 5 | May 19 | Jun 29 | 73.3 | 73.2 | 87.6 | 1.3 | 100.7 | Jun 06 |
| Climate Division 1 | 19.4 / 19.7 | 19.4 / 19.7 | 9.2 | 82.0 / 61.2 | 102.0 / 79.3 | Jul 14 | 0.7 | 3.8 | 6 | May 31 | Jul 23 | 75.8 | 75.7 | 87.3 | 1.2 | 102.0 | Jul 05 |
| Climate Division 2 | 19.7 / 19.8 | 19.7 / 19.8 | 9.6 | 82.2 / 60.7 | 103.1 / 79.3 | Jul 20 | 0.7 | 3.7 | 6 | May 21 | Jul 03 | 74.9 | 74.6 | 87.8 | 1.2 | 103.1 | Jun 13 |
| Climate Division 3 | 19.7 / 19.4 | 19.7 / 19.4 | 8.8 | 82.3 / 60.6 | 102.2 / 79.7 | Jul 19 | 0.7 | 3.4 | 5 | May 20 | Jul 04 | 72.7 | 72.6 | 87.5 | 1.4 | 102.2 | Jun 17 |
| Climate Division 4 | 20.1 / 19.6 | 20.1 / 19.6 | 9.0 | 83.2 / 61.1 | 102.4 / 79.4 | Jul 18 | 0.7 | 3.4 | 5 | Jun 05 | Jul 06 | 76.5 | 76.4 | 89.5 | 1.1 | 102.4 | Jun 19 |
| Climate Division 5 | 19.8 / 19.5 | 19.8 / 19.5 | 9.1 | 82.0 / 59.8 | 103.4 / 79.8 | Jul 16 | 0.7 | 3.4 | 6 | May 30 | Jul 08 | 75.0 | 74.8 | 89.0 | 1.3 | 103.4 | Jun 18 |
| Climate Division 6 | 19.8 / 19.4 | 19.8 / 19.4 | 9.1 | 81.7 / 58.6 | 101.5 / 77.8 | Jul 23 | 0.9 | 3.4 | 6 | May 30 | Jul 08 | 73.3 | 73.4 | 87.9 | 1.3 | 101.5 | Jun 20 |
| Climate Division 7 | 20.3 / 19.6 | 20.3 / 19.6 | 8.0 | 80.3 / 55.0 | 99.7 / 74.4 | Jul 12 | 0.8 | 3.4 | 7 | May 30 | Jul 03 | 71.4 | 71.2 | 85.7 | 1.2 | 99.7 | Jun 14 |
| Climate Division 8 | 20.1 / 19.3 | 20.1 / 19.3 | 7.1 | 72.6 / 51.3 | 92.3 / 69.3 | Jul 10 | 0.6 | 3.7 | 5 | May 24 | Jul 03 | 64.5 | 64.6 | 78.0 | 1.2 | 92.3 | Jun 09 |
| Allegany | 20.4 / 19.4 | 20.4 / 19.4 | 7.4 | 79.1 / 54.0 | 99.5 / 74.2 | Jul 09 | 0.8 | 3.5 | 5 | May 20 | Jun 25 | 69.9 | 69.8 | 84.9 | 1.2 | 99.5 | Jun 06 |
| Anne Arundel | 19.9 / 19.4 | 19.9 / 19.4 | 9.0 | 82.5 / 60.9 | 102.6 / 80.4 | Jul 18 | 0.7 | 3.4 | 5 | May 24 | Jul 04 | 75.2 | 75.0 | 89.8 | 1.3 | 102.6 | Jun 15 |
| Baltimore | 19.9 / 19.6 | 19.9 / 19.6 | 9.0 | 81.9 / 58.6 | 102.6 / 78.3 | Jul 17 | 0.8 | 3.5 | 6 | May 25 | Jul 04 | 74.9 | 74.9 | 88.6 | 1.3 | 102.6 | Jun 16 |
| Calvert | 19.5 / 19.3 | 19.5 / 19.3 | 8.8 | 81.2 / 59.8 | 102.2 / 79.6 | Jul 15 | 0.7 | 3.3 | 5 | May 23 | Jul 05 | 74.8 | 74.7 | 87.3 | 1.4 | 102.2 | Jun 18 |
| Caroline | 19.9 / 19.4 | 19.9 / 19.4 | 9.3 | 84.0 / 61.0 | 103.5 / 78.8 | Jul 09 | 0.9 | 3.3 | 5 | Jun 02 | Jul 17 | 77.5 | 77.3 | 89.5 | 1.2 | 103.5 | Jun 30 |
| Carroll | 20.5 / 19.2 | 20.5 / 19.2 | 8.9 | 81.0 / 57.6 | 100.1 / 77.0 | Jul 23 | 0.9 | 3.2 | 5 | Jun 03 | Jun 27 | 72.8 | 72.8 | 86.7 | 1.1 | 100.1 | Jun 12 |
| Cecil | 19.6 / 19.5 | 19.6 / 19.5 | 8.8 | 81.2 / 58.8 | 103.1 / 78.2 | Jul 19 | 0.7 | 3.5 | 6 | Jun 25 | Jul 29 | 76.2 | 76.1 | 88.0 | 1.2 | 103.1 | Jul 05 |
| Charles | 19.9 / 19.4 | 19.9 / 19.4 | 8.9 | 83.7 / 61.2 | 102.3 / 79.5 | Jul 15 | 0.7 | 3.3 | 5 | May 16 | Jul 05 | 74.1 | 74.0 | 88.8 | 1.4 | 102.3 | Jun 19 |
| Dorchester | 19.9 / 19.6 | 19.9 / 19.6 | 9.6 | 81.7 / 60.5 | 103.3 / 79.5 | Jul 17 | 0.7 | 3.7 | 6 | May 23 | Jun 22 | 75.5 | 75.1 | 88.1 | 1.2 | 103.3 | Jun 16 |
| Frederick | 19.8 / 19.8 | 19.8 / 19.8 | 8.6 | 81.3 / 57.7 | 100.0 / 77.6 | Jul 22 | 1.0 | 3.3 | 7 | May 15 | Jun 21 | 71.5 | 71.6 | 86.7 | 1.2 | 100.0 | Jun 06 |
| Garrett | 20.0 / 19.2 | 20.0 / 19.2 | 7.1 | 72.6 / 51.3 | 92.3 / 69.4 | Jul 07 | 0.6 | 3.7 | 5 | May 28 | Jul 04 | 65.5 | 65.6 | 78.3 | 1.1 | 92.3 | Jun 12 |
| Harford | 20.1 / 19.7 | 20.1 / 19.7 | 8.7 | 82.1 / 59.0 | 103.5 / 78.1 | Jul 16 | 0.7 | 3.6 | 6 | Jun 15 | Jul 25 | 75.6 | 75.5 | 89.1 | 1.3 | 103.5 | Jul 06 |
| Howard | 20.2 / 19.2 | 20.2 / 19.2 | 9.0 | 81.9 / 58.8 | 101.0 / 77.9 | Jul 23 | 0.8 | 3.4 | 6 | Jun 09 | Jul 06 | 74.0 | 74.0 | 87.8 | 1.1 | 101.0 | Jun 19 |
| Kent | 19.8 / 19.4 | 19.8 / 19.4 | 8.8 | 81.9 / 60.0 | 103.5 / 80.1 | Jul 16 | 0.7 | 3.5 | 6 | May 30 | Jul 08 | 74.8 | 74.6 | 89.2 | 1.3 | 103.5 | Jun 18 |
| Montgomery | 20.5 / 19.4 | 20.5 / 19.4 | 8.9 | 82.2 / 59.9 | 100.3 / 77.6 | Jul 25 | 0.9 | 3.4 | 6 | May 26 | Jul 04 | 73.8 | 73.8 | 87.9 | 1.3 | 100.3 | Jun 17 |
| Prince George's | 20.2 / 19.6 | 20.2 / 19.6 | 8.9 | 83.3 / 60.8 | 102.3 / 78.7 | Jul 19 | 0.7 | 3.4 | 5 | Jun 05 | Jul 06 | 76.4 | 76.4 | 89.1 | 1.1 | 102.3 | Jun 21 |
| Queen Anne's | 19.8 / 19.8 | 19.8 / 19.8 | 9.4 | 82.9 / 60.4 | 103.3 / 79.7 | Jul 11 | 0.7 | 3.5 | 6 | Jun 01 | Jul 08 | 76.0 | 75.8 | 88.9 | 1.3 | 103.3 | Jun 19 |
| Somerset | 19.3 / 19.3 | 19.3 / 19.3 | 9.2 | 81.8 / 61.6 | 102.4 / 80.1 | Jul 11 | 0.7 | 3.8 | 6 | Jun 10 | Jul 12 | 75.3 | 74.9 | 87.9 | 1.2 | 102.2 | Jul 02 |
| St. Mary's | 19.4 / 19.3 | 19.4 / 19.3 | 8.8 | 81.2 / 59.8 | 102.3 / 79.9 | Jul 11 | 0.7 | 3.2 | 5 | Jun 01 | Jul 07 | 73.4 | 73.3 | 87.7 | 1.3 | 102.3 | Jun 22 |
| Talbot | 19.9 / 19.7 | 19.9 / 19.7 | 9.5 | 82.3 / 60.9 | 102.8 / 79.8 | Jul 15 | 0.7 | 3.5 | 6 | May 28 | Jul 03 | 74.7 | 74.5 | 87.9 | 1.3 | 100.4 | Jun 12 |
| Washington | 20.3 / 19.7 | 20.3 / 19.7 | 8.3 | 81.8 / 56.4 | 100.5 / 76.2 | Jul 16 | 0.8 | 3.4 | 7 | May 08 | Jun 14 | 69.6 | 69.5 | 86.5 | 1.2 | 100.5 | May 30 |
| Wicomico | 19.4 / 19.5 | 19.4 / 19.5 | 9.0 | 82.7 / 60.9 | 103.1 / 78.9 | Jul 11 | 0.7 | 3.8 | 6 | May 31 | Jul 23 | 76.0 | 75.9 | 87.6 | 1.2 | 103.1 | Jul 05 |
| Worcester | 19.5 / 19.8 | 19.5 / 19.8 | 8.6 | 81.6 / 61.2 | 101.4 / 79.7 | Jul 09 | 0.6 | 3.6 | 6 | May 12 | Jun 21 | 70.6 | 70.5 | 85.7 | 1.2 | 97.3 | May 30 |
| Baltimore city | 19.8 / 19.6 | 19.8 / 19.6 | 9.0 | 82.3 / 60.4 | 104.2 / 81.2 | Jul 20 | 0.8 | 3.6 | 6 | Jun 01 | Jul 08 | 75.6 | 75.6 | 90.4 | 1.2 | 104.2 | Jun 18 |