The latest July Weather forecasts show an emerging cooler trend for the eastern United States, with a dynamic jet stream pattern. The atmospheric pressure pattern is forecast to bring a high-pressure anomaly over the western United States, shaping the July weather, along with a strong low-pressure area over Canada.
July is already the second month of meteorological Summer, and it is usually the warmest month across the United States and Canada.
We will first look at the amplified jet stream pattern in June, and how it shaped the first Summer month over North America. Then you will see how the latest forecasts indicate that July weather patterns will bring a cooler trend to the eastern United States, with a powerful ridge rising around mid-July and extending into Canada.
SUMMER JET STREAM WEATHER
As mentioned, July is the second month of the meteorological summer, which covers the three warmest months of the year: June, July, and August. It is based on actual weather patterns and temperatures, unlike astronomical summer, which is based on the calendar and Earth’s position around the Sun.
With that in mind, the first Summer month has just finished, and it has featured a very dynamic weather pattern. Below is the pressure anomaly for June over North America, and what stands out right away is the strong low-pressure area over Canada with an extension into the central United States.
The image above is an average for almost the whole month, so naturally, the daily weather patterns were more varied. But this helps us to see the prevailing weather pattern and where the main pressure areas are located, and the jet stream between them.
The jet stream is a narrow, fast-moving stream of air at higher altitudes (9-13km or 6-8 miles). It helps to shape our daily weather, steer pressure systems, and can create floods or droughts. It is directly linked to daily to monthly weather development.
A strong low-pressure area over Canada helped to amplify the jet stream over the northern United States and southern Canada. You can see the jet stream analysis for June in the image below, with the amplified jet stream marked.
This helped bring a cooler and more unsettled weather pattern to southern and southeastern Canada, as well as parts of the northern and eastern United States. Below is the June 2025 temperature anomaly over the United States and Canada, which shows mostly warmer-than-normal weather over the west, with a more dynamic pattern over the eastern half of the U.S. and Canada.
If we look at the temperatures over the first half of the month below, you can see mostly normal to below-normal temperatures over the eastern United States and eastern Canada. This was a result of an amplified jet stream over the northern United States and southern Canada.
Below, you can also see the June precipitation analysis from CPC data, and it shows a dry month over the northern and northwestern United States and western and northern Canada. But you can see more rainfall over the eastern half of the United States, the southern U.S., and southeastern Canada.
This is an expected pattern where we see less precipitation in the rear part of the jet stream, and more precipitation and (amplified) severe weather over the front (exit) part of the jet stream.
But as we now enter July, the latest model predictions show another shift in the weather patterns and the return of a cooler trend over the eastern United States.
THE SECOND SUMMER MONTH FORECAST
Below is the pressure anomaly forecast for the first week of July. You can see an amplified ridge over the central and eastern United States, with a low-pressure area over northern Canada. There are also local low-pressure areas entering the western United States and a low-pressure disturbance over the eastern U.S. coast.
The temperature forecast for the same period shows warmer-than-normal weather over much of the northern half of the United States and southern Canada. This is due to the amplified ridge, but you can see some below-normal temperatures over northern Canada, the southwestern United States, and Florida.
But we can also look at some individual days, and below you can see the forecast for the end of this week, where a very warm airmass will expand over the central and eastern United States, also pushing far into eastern Canada.
At the same time, an airmass with below normal temperatures will drop from the north over the western United States and western Canada, at the rear end of the ridge.
The daily temperatures in this period are forecast to reach into the 90s and higher over the central and eastern United States, with 90s also reaching the upper Midwest. Temperatures in the 80s are also forecasted to extend deep into eastern Canada.
The precipitation forecast for the first week of July shows a rather dry trend over the eastern United States and southwestern Canada, due to the high-pressure ridge. But you can see more rainfall over the southwestern U.S. and a very interesting area around Florida.
The precipitation area around Florida also shows lower pressure and increased convection (storms). It’s currently under a 40% chance of tropical system development over the next 7 days, according to the latest forecast by the National Hurricane Center, so it’s an area to watch closely.
A COOLER WEATHER TREND EMERGING
Below is the latest pressure anomaly forecast for the second week of July. You can see an unusually strong low-pressure area over northern Canada and the polar regions. There is also an extension of the low-pressure area indicated over the eastern United States, and a ridge rising over the west and up into southern Canada.
Because a low-pressure area spins counter-clockwise in the Northern Hemisphere, that means a northerly flow on its rear side and a southerly flow on its front side. You can see this in the example image below, which shows how pressure areas over the United States spin and what flow they create.
The image above is more centered on winter patterns, but the overall flow is always the same. You can see that by looking at the temperature forecast below for the second week of July. You can see the below-normal temperatures over the eastern United States under the northerly flow.
A strong ridge in the west will bring much warmer-than-normal temperatures over the western United States and western Canada. A strong area of below-normal temperatures will also persist over the northern flow in northern Canada.
Below is an example of the surface temperature anomaly for mid-July. This is a single forecast run, so it’s not a fixed scenario, but just an example of a weather development in such a pattern. You can see a cooler airmass entering eastern Canada and the eastern United States.
A weather pattern with a low-pressure area over the eastern United States or southeastern Canada always has a good chance of bringing a cooler airmass from the north into the eastern half of the United States.
The official NOAA temperature outlook for this period also indicates warmer weather in the western and northwestern United States during this period. But you can also see a large normal-to-below-normal area trend over the Midwest and parts of the eastern and central United States.
The precipitation forecast for this period shows a drier trend over the northern United States and southern Canada. But more rainfall is forecast over the eastern and southeastern United States, due to lower pressure and potential frontal systems.
As we go beyond this mid-July period, we start to use the extended range forecasting system. This is used to provide us with weekly weather trends that can indicate areas of above-normal or below-normal pressure areas and temperatures.
A STABLE WEATHER ANOMALY
Going into the third week of July, the latest extended range forecast shows the continued presence of the broad low-pressure area over northern Canada. This amplifies the jet stream over north-central Canada, and can also evolve further to bring lower pressure into the eastern United States as indicated.
A ridge is fixed over the western United States, which will bring a warmer airmass into a large part of North America.
You can see this in the image below, which shows the temperature forecast for the same period. A warmer airmass spreads across the northern and central United States and into southern Canada. But a cooler trend still prevails over the eastern and southeastern United States and over northern Canada and Alaska under the broad low-pressure area.
This is just the latest forecast trend, which always seems to understate the cooler anomalies. So as we get closer to this period, it is likely that the cooler anomalies will get stronger and expand over a larger area of the United States, if the pressure pattern persists.
The main rainfall area during this period is forecasted over the southeastern United States, due to a low-pressure area over the eastern United States. The central and northern U.S. and southwestern Canada are forecast to receive less rainfall than normal due to a high-pressure system.
Once a cold front is unleashed from the north, if the high-pressure system is positioned properly over the east, it can lift up into Canada, allowing the further expansion of cooler air and lower pressure into the eastern United States.
THE FINAL WEEK WEATHER FORECAST
The final week of July shows little change in the extended range forecast. You can still see the presence of a broad low-pressure area over northern Canada and a low-pressure signature over the eastern United States. A high-pressure ridge looks to be a fixed feature of the July pressure anomaly overall.
You can also see that the temperature forecast is trending in a very similar direction to the previous week. But some of this is also just down to the model itself and the fact that this is a very extended range forecast. Still, week-to-week changes are usually seen, and this just shows a potential for a stable weather pattern.
You can see the same warm anomaly spreading over the central and northern United States and southern Canada. But you can also see the normal to below-normal hints over the eastern and southeastern United States.
This is just the latest forecast trend, which always seems to understate the cooler anomalies. So as we get closer to this period, it is likely that the cooler anomalies will get stronger and expand over a larger area of the United States, if the pressure pattern persists.
The above-normal rainfall area in the final week of July is forecast to shift a bit further north compared to the previous week. It covers the eastern United States in the latest forecast, and can indicate a broader drop in pressure over the east.
Less rainfall than normal is still expected over the central and northern United States and southwestern Canada.
JULY WEATHER OUTLOOK AND TROPICS
Below is the official monthly outlook for July, issued by NOAA. It shows a warmer anomaly over the western half of the United States. But notice the eastern United States, where we see an area of “normal” temperatures or equal probability. This aligns well with all the forecasts above, for a normal to cooler trend over the eastern U.S. and a lower pressure pattern.
The official precipitation forecast for July is as expected, with a drier area over the northwestern United States. But more rainfall than normal is forecast over the eastern United States, due to the frequent pressure disturbances and potential weather fronts.
As we look at July overall, we also have to look at the tropics, because this is usually the month when tropical activity starts to increase.
Below is the precipitation forecast for July, from the extended weather forecasting system by ECMWF. You can see a very dry area across the main development region (MDR). This indicates a much reduced potential for tropical storm formation, limiting tropical activity in July.
One of the reasons for this reduced activity is also the so-called “Atlantic Niña” anomaly in the tropical Atlantic. You can see this cold anomaly in the image below from NOAA Coral Watch. We have marked the two main areas, the cold Atlantic Nina (right) and the neutral ENSO regions in the Pacific (left).
Below is a high-resolution video that shows a rapid ocean cooling process in the Atlantic, made from NOAA CRW analysis. It shows the emergence of the Atlantic Niña event over the past 30 days.
The warmer anomalies in the eastern ENSO regions also tend to signal a reduced potential for tropical storm development in the Atlantic. So, from the latest analysis and forecast data, you can see that the hurricane season is expected to remain quiet with low risk for a United States landfall.
Forecast images in the article are from WeatherBell using a commercial license.
We will keep you updated on the global weather pattern development, so don’t forget to check back. Also, if you have seen this article in the Google App (Discover) feed, click the like button (♥) or a star there to see more of our forecasts and our latest articles, and weather forecasts.
