A record-breaking heat wave continued in the US, exacerbating wildfires across some western states, including part of California and Washington and producing unhealthy air quality levels. The hottest temperature ever recorded in San Francisco occurred on 1st Sept – 41degC. Other records were recorded in LA, Portland, Oregon and Montana.
Hurricane Irma strengthened to a Category 5 hurricane on 5th Sept with maximum sustained winds of 185 mph, becoming the strongest storm in the Atlantic Basin since Wilma in 2005. For more information about Irma click here >>
On the 21st Sept, snow fell in California on what was officially classed as the last day of summer - the unexpectedly early turn in the weather caused dangerous travel conditions, with one man killed due to a car crash. Mammoth Lakes in Sierra Nevada reported 3 inches of snow.
Hurricane Maria devastated Dominica, an island in the Caribbean, on 18th September,, and went on to hit the southernmost Virgin Islands and Puerto Rico. For more information about Maria click here >>
The end of September (and the first week of astronomical autumn) saw high temperatures from the Midwest to the north-eastern United States, producing higher temperatures than those seen in summer, with some locations recording record highs. A large area of high pressure centred over the Great Lakes and Ohio Valley was the culprit of the unusual heat and humidity.
At least six people were killed after heavy rainstorms and flooding in the Italian city of Livorno on the 10th.
A powerful storm in western Romania killed eight people and injured at least 67 in and around Timisoara on the 17th , as winds of up to 60 mph brought down trees and tore off roofs.
On the 15th, tens-of-thousands of people were evacuated from Vietnam's coast as a "most powerful storm in a decade" approached the country. Almost 80,000 people left their homes while local authorities tore down trees and cut power in some areas as Typhoon Doksuri made its way towards land. Offshore, wind speeds hit 102 mph, according to the Hong Kong Observatory.
A powerful typhoon has ripped through southern Japan giving torrential rain, grounding hundreds of flights and stopping train services on the 17th. Typhoon Talim hit Kyushu, the southernmost of Japan's four main islands with winds of up to 105 mph.
More than a month's worth of rain fell across parts of Mumbai in just 24 hours from the 21st. Rainfall totalling 303.7 mm was reported in the city, the second highest 24-hour September rainfall total on record.
Australian temperature records tumbled in September, with the country experiencing the hottest day since records began, and New South Wales breaking that record twice within a few days. The hottest September day for a Queensland town was recorded at Birdsville on 17th. The mercury rose to 42.5C on Wednesday afternoon, surpassing the previous state record by 0.1 degC.