Following a pair of historic heat waves during the summer, warmth will be limited in the coming months.
Meanwhile, unsettled weather will increase with many regions expecting frequent storms and rainfall.
Parts of the British Isles had a taste of autumn in August as wet and windy weather struck the region on multiple occasions.
As autumn progresses, the threat of significant windstorms will be on the rise across Ireland and United Kingdom.
Impacts from the storms will occasionally spread farther south and east impacting locations from northern France to Netherlands and Denmark.
These windstorms will bring the risk of power cuts and significant travel disruption. Downpours from each storm will also elevate the risk of flash flooding.
On top of the risk of windstorms, areas from northern France to the British Isles may have to contend with one or two post-tropical storms from the Atlantic Ocean.
The greatest risk for these storms will be during the months of September and October.
“The combination of post-tropical storms and wind storms will make for a wetter-than-normal autumn,” AccuWeather Senior Meteorologist Alan Reppert said.
While the British Isles will be at risk for multiple damaging windstorms during the autumn, there will still be several stretches of dry and mild weather throughout the season.
During these tranquil spells, days will feature abundant sunshine and temperatures will be near to above normal.
Following the record-breaking summer, no further heat waves are expected across northwestern Europe.
The one region most likely to endure lengthy unseasonable heat during the autumn will be Portugal and Spain.
This warmth will also spread into southern France at times; however, even the hottest weather of September will not compare to the intense summer heat waves.
The seasonably hot, dry weather during September will also prolong the risk of wildfires following months of intense summer heat combined with infrequent rainfall.
A sharp change in the weather is expected during the month of October as storms from the Atlantic return to the Iberian Peninsula.
This pattern will bring much-needed rainfall as well as an end to any lasting unseasonable warmth.
While the rainfall will be largely beneficial, downpours falling on the hard, dry ground will elevate the risk of flash flooding.
“These downpours will also dramatically lower the risk of wildfires in the region,” Reppert said.
A few of these storms may supply locally damaging winds, especially across northern Portugal and northwestern Spain.
Following a summer highlighted by multiple historic heat waves, locations from France to Poland and Slovakia can expect a more comfortable autumn with lengthy dry spells and a lack of intense heat.
While temperatures for the season as a whole will likely be above normal in most locations, days will be pleasant for outdoor activities in September and October.
Most days in September will feature high temperatures in the low to mid-20s C (upper 60s and 70s F) in Paris, Berlin and Warsaw.
While temperatures will trend downwards in October and November, sunshine will still provide ample warmth during the afternoon hours for outdoor plans.
A sharp change in the weather is possible during mid- and late November as cold air from Russia attempts to press westward across Europe.
This cold air may settle as far west as Germany, bringing an unseasonable chill to Berlin, Prague and Warsaw.
The cold air mass will also elevate the chance of snowfall.
While higher elevations are most likely to get accumulations, snowflakes may mix with rainfall or even briefly coat the ground in lower elevations during this time.
The lengthy dry spells of the autumn season will heighten concerns for drought following a drier-than-normal summer with unseasonable heat.
“Concern is rising for significant impacts to agriculture in France and Germany,” Roys said.
Meanwhile, the dry weather will be beneficial for harvesting from Poland into Belarus and Czechia.
Occasional bouts of stormy weather across Italy and the Balkan Peninsula during the summer will continue into the autumn.
Severe thunderstorms struck multiple locations from Italy to Romania and Greece throughout the summer, and both of these threats will remain concerns during the month of September.