GWC’s Weather Week That Was – May 11-17, 2025
Greg’s Weather Center – Data for the Week of May 11-17, 2025
Location: South Plainfield, NJ
Latitude: 40.58 N
Longitude: 74.42 W
| Date | High Temp | Low Temp | Diurnal Range | Rainfall | Peak Rainfall Rate | High Pressure | Low Pressure | Pressure Change |
| 5/11/2025 | 79 | 45 | 34 | 0.00 | 0.00 | 30.27 | 30.08 | 0.19 |
| 5/12/2025 | 75 | 46 | 29 | 0.00 | 0.00 | 30.32 | 30.12 | 0.20 |
| 5/13/2025 | 70 | 56 | 14 | 0.29 | 0.51 | 30.16 | 30.08 | 0.08 |
| 5/14/2025 | 62 | 59 | 3 | 1.86 | 4.14 | 30.10 | 29.92 | 0.18 |
| 5/15/2025 | 69 | 60 | 9 | 0.23 | 2.31 | 29.92 | 29.78 | 0.14 |
| 5/16/2025 | 75 | 63 | 12 | 0.56 | 2.44 | 29.79 | 29.65 | 0.14 |
| 5/17/2025 | 84 | 63 | 21 | 0.00 | 0.00 | 29.65 | 29.40 | 0.25 |
Temperature for the Week of May 11-17, 2025
- Average High Temperature: 73.4°
- Max Temperature: 84° on May 17th
- Min Temperature: 45° on May 11th
Diurnal Range for the Week of May 11-17, 2025
NOTE: The diurnal range of temperature is the difference between the high temperature and low temperature on a given day.
- Average Diurnal Range of Temperature: 17.4°
- Max Diurnal Range: 34° on May 11th
- Min Diurnal Range: 3° on May 14th
Rainfall for the Week of May 11-17, 2025
- Average Daily Rainfall: 0.42 inches
- Max Rainfall: 1.86 inches on May 14th
- Min Rainfall: 0.00 inches on May 11th, 12th, and 17th
- Peak Rainfall Rate: 4.14 inches per hour on May 14th.
Pressure for the Week of May 11-17, 2025
- Max Pressure: 30.32 on May 12th
- Min Pressure: 29.40 on May 17th
- Largest Pressure Drop: 0.38 of an inch or 12.7 millibars from 2:11 AM on May 16th to 4:00 PM on May 17th
- Largest Pressure Rise: 0.24 of an inch or 8.0 millibars from 12:00 AM on May 11th to 7:48 AM on May 12th
Summary
The week of May 11th to May 17th, 2025 was the stormiest since the beginning of April at Greg’s Weather Center. Total rainfall for the week was 2.94 inches with over half of it happening on Wednesday, May 14th. The maximum rainfall rate of 4.14 inches per hour occurred that afternoon. Most of the rainfall occurred from 1:00 to 3:00 PM (1.21 inches). There were four straight days of measurable rainfall.
The total rainfall for the week represented more rain than the entire month of April (2.47 inches). This week’s rain accounted for over 71 percent of the month-to-date total for May 2025. Almost three times more rain fell over those two hours on May 14th than during the entire month of January. Over six times more rain fell in that timeframe than during the last 18 days of April (0.19 of an inch).
From a temperature standpoint, this week was several degrees warmer than last. The average high temperature was over three and a half degrees warmer than it was the week before. The average low was 2.3 degrees warmer. GWC had its first 80-degree day in two weeks with a high of 84 degrees on Saturday, May 17th. It was the 9th day of 80-degree weather in Northwestern Middlesex County.
In addition to the torrential downpour on Wednesday, there was a threat of severe weather on Friday and Saturday. The main threat was on Friday. The Storm Prediction Center issued a Severe Thunderstorm Watch for most of the Garden State until 5:00 PM on Friday. A Mesoscale Convective System (MCS) brought devastating tornadoes to Wisconsin and Michigan headed east and would bring severe weather to South Jersey.
Fortunately for Central Jersey and points northward, there were morning clouds and fog that curtailed the development of severe weather. Nevertheless, thundershowers still brought over another half an inch of rain (0.56 of an inch). A second Severe Thunderstorm Watch was issued for South Jersey until midnight. Saturday’s severe weather threat never materialized as the day turned out to be sunny and breezy despite the pressure falling to 29.40 inches.