GWC Monthly Summary – June 2025
Review – June 2025 – The Heat Emerges while Up and Down Rain Cycle Continues
The month of June 2025 saw the summertime heat emerge while the up-and-down rain cycle continued. It took some time for the heat to develop at Greg’s Weather Center, but when it did, it came with a vengeance. The first 90-degree day didn’t occur on June 19th, but it was followed up by the most torrid heatwave since 2012. Meanwhile, the rainfall returned to a down phase with less than two and a quarter inches after the wettest May on record at GWC.
View Local Climatological Data – Greg’s Weather Center – June 2025
Rainfall – June 2025
After the wettest May on record and the 9th wettest month of all time at GWC, the rainfall pattern continued to show a Jekyll and Hyde behavior.
Only 2.20 inches of rain fell at Greg’s Weather Center in South Plainfield, NJ. Most of that rainfall occurred over the two-week period from June 7th to June 21st.
Over those two weeks, eight of the 11 days with measurable rainfall, and six of the seven days with rainfall amounts of at least a tenth of an inch.
| Date | Total Rainfall |
| June 14-16, 2025 | 0.80 inches |
| June 9-10, 2025 | 0.52 inches |
| June 30, 2025 | 0.49 inches |
| June 19, 2025 | 0.27 inches |
| June 7, 2025 | 0.10 inches |
| June 28, 2025 | 0.05 inches |
| June 17, 2025 | 0.04 inches |
Wind – June 2025
There was not a lot of wind during June 2025. Much of that was attributed to the lack of storms and rainfall.
Over the course of the month, there were only five days with double-digit wind gusts. The highest of those five wind gust measurements was only 13 miles per hour.
The maximum two-minute wind speed was only 6 miles per hour. In summation, the month of June 2025 was uneventful in terms of wind.
Temperature – June 2025
The story of this month was the heat and warmth that developed. There were no days when the minimum or low temperature was lower than freezing. Six days where the high was at least 90.
Included in those six days was the first 100-degree day in almost 13 years. The first heatwave of 2025 yielded a three-day average of 99 degrees. Meanwhile, the humidity also became a factor with a peak heat index of 120 degrees on June 23rd, followed by a heat index of 116 on June 24th.
There were 18 days of at least 80-degree weather. The June 2025 tally pushed the year-to-date total to 27. Compared to 2024, the number of 80-degree days is running six days behind. Looking back to 2023, this year is running 10 days ahead.
The average high for the month was 81 degrees while the average low was 63. The average temperature for June 2025 was 71 degrees. Looking at the diurnal temperature range, the average for the month was 18 degrees.
Pressure – May 2025
The average barometric pressure for the month was 29.89 inches of Hg, or 1012 millibars at GWC. The lowest pressure was 29.62 inches or 1003 millibars on June 1st. The highest pressure was 30.10 inches or 1010 millibars on June 27th.
There were a few days with storms, but the ones that became stormy were quite potent. On the first 90-degree day of the year, June 19th, storms developed in the afternoon that produced over a quarter of an inch of rain in a very short time. The peak rainfall rate was 4.36 inches per hour at 12:33 PM. Approximately 0.15 of an inch fell in just six minutes.
