River. Image by Tim Hill from Pixabay
Latest Outlook
Outlook map for October 2021, showing that River flows and groundwater levels in October are expected to be normal to above normal across the UK.

October 2021 Hydrological Outlook

Period: From October 2021      Issued on 07.10.2021 using data to the end of September 2021

River flows across the UK are likely to be normal to above normal for October. Groundwater levels are likely to be within the normal range, with localised exceptions for October, and within the normal range for October-November-December.

Rainfall:

September rainfall was below average for the majority of the UK, with large areas experiencing less than 70 percent of the 1981-2010 average rainfall. A few localised areas of southern England and south Wales saw some wetter weather. Rainfall has been below average for most of the UK (with the exception of southern England) for the past six months.

The rainfall outlook for the UK for October (issued by the Met Office on 23.09.2021) is that rainfall is slightly more likely to be normal than dry. For October-November-December as a whole, it is slightly more likely to be normal than wet.

River flows:

River flows in September were normal to exceptionally low across the UK, though above normal to notably high flows were recorded in some catchments over the Chalk aquifer of south-eastern England. The lowest flows were focussed in northern England.

Despite low September flows, heavy rainfall at the end of September and first week of October has caused most river levels to rise. Flows across the UK are therefore likely to be normal to above normal for October. Flows in Scotland are likely to be within the normal range, but with considerable uncertainty due continuing issues with data access. The three month forecast suggests that flows are most likely to be within the normal range, though this is uncertain at this transitional time of year.

Groundwater:

Groundwater levels in September were normal to above normal across the UK. Above normal to exceptionally high groundwater levels were recorded along the south coast, and in the northern limestones and sandstones.

Groundwater levels are likely to be within the normal range for October and October-November-December as a whole, though above normal and below normal flows are expected in some localised boreholes for October.

Note that due to continuing issues with data access, no data are available for Scotland.