donsutherland1

That’s true. With summers continuing to warm, there has been a sudden explosion of truly extreme summers. It’s too soon to draw too many conclusions about that, but in general extremes have increased in a non-linear fashion as the climate has warmed.

The climate models couple the ocean and atmosphere in forecasting circulation changes. To date, the trends in the Southwest (including part of California) and Northeast are consistent with what is expected from the circulation changes. The 1960s were snowier, because the cold was so much greater than it has been recently. There was greater opportunity for precipitation to fall in the form of snow than there is today. During winters 1960-61 through 1969-70, the mean winter temperature was 32.6°, four winters had mean temperatures at or below 32°, with the warmest winter having a mean temperature of 35.9°. During 2010-11 through 2024-25, the mean winter temperature was 37.1° (above the warmest winter of the 1960s), the coldest winter was 32.7° (above the mean figure for the 1960s), and four winters had mean temperatures of 40° or above. The rapid increase in warmth has more than offset the wetter climate. As a result, New York City's snowfall is likely in the early stages of a secular decline. By the mid-2030s, it will be clear whether snowfall has truly entered a long-term decline, even as there will still be snowier cycles and snowier winters. I suspect that the 30-season mean snowfall figure will reach or fall below 20.0" at Central Park by the mid-2030s.

For purposes of illustration, below is an example of why Shewchuk's arguments are deeply flawed. The illustration examines the change in Phoenix's mean summer minimum temperatures. Shewchuk's dismissal of adjusted data would mean that Phoenix's climate has seen summer minimum temperatures increase almost 1.5° per decade due to climate change (natural and anthropogenic). His claims would ignore the impact that the emergence and then rapid growth of Phoenix's Urban Heat Island Effect has had on summer minimum temperatures. In 1941, the beginning of the first 30-year period under consideration, Phoenix had a population of just over 65,000. In 2024, Phoenix's population was 1,682,515. During 1940-1980, Phoenix's population grew an average of 6.4% per year; since 1980, it has been growing at about 1.8% per year. The sharper rise in the raw data during the first part of the chart and flattening afterward provide a footprint of the growth in the UHI. If one were seeking to understand how fast Phoenix's climate has been warming, one would need to exclude artificial factors e.g., UHI. That's what the adjustments do. They remove the impacts of siting changes (location, features such as new buildings, etc.), UHI, time of observation bias, etc. The adjustments allow for comparability. They make robust scientific analysis possible.

There are cycles and there are also longer-term trends. For example, New York City is seeing increasing precipitation (as expected from climate change). Its cycles continue and a drier cycle will commence at some point, but the overall trend is for greater annual precipitation. In contrast, parts of California and the Desert Southwest are in an aridification trend. There will be wetter cycles, but the overall trend is reduced precipitation.

Yesterday, Phoenix saw its first measurable rainfall of Monsoon Season when 0.16” fell. It was the 35th biggest first measurable rainfall of Monsoon Season. Finally, drier Monsoon seasons are often correlated with more intense heat. Phoenix has been evolving toward drier monsoon seasons and hotter summers.

Generally warm weather will prevail through Saturday. New York City will see highs in the middle to perhaps upper 80s during this stretch. Parts of the region could experience some thunderstorms tomorrow afternoon or evening. After that, the next rainfall will likely occur during a frontal passage early next week. Excessive heat does not appear likely to return through at least the first week of July. There remains some potential for a shot of more significant heat during the July 6-8 period. The worst of the heat, should it develop, will likely occur away from the coastal plain. The ENSO Region 1+2 anomaly was +1.0°C and the Region 3.4 anomaly was 0.2°C for the week centered around June 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.47°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. Neutral ENSO conditions will likely continue through at least late summer. The SOI was +7.32 today. The preliminary Arctic Oscillation (AO) was +1.176 today.

July Mean Temperatures and Precipitation at Central Park: In general, drier outcomes are correlated with hotter outcomes. However, 1991-2020 has become both warmer and wetter than the 1961-1990 base period.

Yes. It should have easily beaten the record (46 +/- 5 days using the pre-2000 summer regression equation).

Yes, all things being equal, a wetter climate can temper heatwave intensity and duration.

That's something the data can't really illustrate. But one would expect similar trends in the nearby locations as one is seeing at Central Park if synoptic developments were largely responsible. Instead, Central Park has been decoupling from the nearby locations when it comes to high temperatures. Indeed, absent the trees, Central Park would likely have had two 100° days so far, including a June record 102° high (pre-2000 regression equation).

Wetter summers but not more frequent rainfall. But the decoupling between Central Park, JFK, LaGuardia, and Newark, which are experiencing similar rainfall trends suggests its Central Park's local environment that is playing the larger role in somewhat reduced high temperatures.

The average number of days with 0.01" or more rainfall per week during the summer hasn't really changed too much. The amount of rainfall has increased and was at its highest 30-year average for the 30-year period ending in 2020. If one goes beyond 2020, the most recent 30-year period (1995-2024) averaged 2.42 days per week with 0.01" or more rain during the summer and average total summer rainfall of 13.99".

The ranges haven't changed too much, though the summer range in Central Park has fallen a bit more than elsewhere (possibly due to the trees’ impact on highs as summer highs have decoupled from those at the surrounding sites most prominently seen with 90°/100° outcomes). But even during the summer, the coefficient of determination has barely moved (0.84 during 1961-1990 to 0.83 at present) when Central Park's range is constructed relative to those of JFK, LaGuardia, and Newark. This suggests that larger forces are responsible for the temperature range than the trees.

A total disgrace and another great leap backward.

These developments provide good examples of how the dense foliage has changed the relationship of Central Park relative to the City's other locations and Newark. The problem is cited in the NOAA's inventory of stations. Unfortunately, the problem is not addressed. Thus, Central Park becomes less representative of the City's actual climate and, instead, an experiment that demonstrates the cooling impact of trees.

Much of the region saw temperatures again reach 90° or above. Parts of the region will experience some heavy thunderstorms this evening and tonight. Generally warm weather will prevail through Saturday. New York City will see highs in the middle to perhaps upper 80s during this stretch. Excessive heat does not appear likely to return through at least the first week of July. However, there is somewhat less certainty than yesterday. There remains some potential for a shot of more significant heat during the July 6-8 period. The ENSO Region 1+2 anomaly was +1.0°C and the Region 3.4 anomaly was 0.2°C for the week centered around June 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.47°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. Neutral ENSO conditions will likely continue through at least late summer. The SOI was +2.65 today. The preliminary Arctic Oscillation (AO) was +1.127 today.

Today became just the third day during the common recordkeeping period where Newark reached 95°, JFK and LaGuardia both reached 90°, but Central Park fell short of 90°. 2025 is the first year with two such days.

So far, Central Park's high today is 88°. Newark has reached 95°. Should Central Park fail to reach 90°, Central Park would record its shortest interval on record between dates where Newark reached 95° or above while Central Park failed to reach 90°. On June 29, 2025, Newark topped out at 95°, while New York City (Central Park) reached 89°. The existing shortest interval is 14 days from May 22, 2021 to June 5, 2021. JFK Airport and LaGuardia Airport have both reached 91° so far today.

JFK Airport has recorded its 8th 90° or above day this year.

July 1, 1911 saw 2.68" of rain in Phoenix (high: 79°) and July 2, 1911 saw an additional 2.81" of rain (high: 82°). The July 2 figure remains the highest July daily amount on record and the two-day figure of 5.49" is the highest two-day figure on record for any two-day period in Phoenix.

June Verification:

Final June numbers:

Almanac of July Records:

Central Park finally reached 90 this afternoon.

June ended on a hot note across much of the New York City area. High temperatures included: Islip: 89° New York City-Central Park: 90° New York City-JFK Airport: 90° New York City-LaGuardia Airport: 91° Newark: 93° New York City is finishing June with a monthly mean temperature of 73.2°. That is 1.2° above normal. June 2025 saw New York City's earliest 80° or above low temperature and an all-time record-tying 3 consecutive 80° or above lows during its heatwave on June 23-25. On June 9, the daily temperature range was just 2° (high: 64°; low: 62°), which tied the June monthly record set on June 8, 1869 and tied on June 11, 1910, June 8, 1916, June 20, 1958, and June 17, 1978. Overall, the June 23-25 heatwave was the most extreme on record for the larger New York City area. Islip (101°) and JFK Airport (102°) set new monthly high temperature records. Bridgeport, LaGuardia Airport, Newark, and White Plains all tied their monthly records. Very warm weather will prevail through mid week. New York City will see highs in the upper 80s. Newark will likely be near or just above 90° on each day during this period. Excessive heat does not appear likely to return through at least the first week of July. However, there is somewhat less certainty than yesterday. There remains some potential for a shot of more significant heat during the July 6-8 period. The ENSO Region 1+2 anomaly was +1.0°C and the Region 3.4 anomaly was 0.2°C for the week centered around June 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.47°C and the ENSO Region 3.4 anomaly has averaged -0.03°C. Neutral ENSO conditions will likely continue through at least late summer. The preliminary Arctic Oscillation (AO) was +1.182 today.