DOI: 10.23637/rmstarain1853-2023-01
title: Dataset: Total Annual Rainfall at Rothamsted 1853-2023

description: This dataset contains the total annual rainfall, at Rothamsted from 1853 - 2023 and is based on continuous daily records measured at the site.
description: Daily rainfall is measured as the total (mm) over the 24-hour period 0900 to 0900 GMT. It includes all precipitation - snow, rain, mist and fog. Rainfall was first recorded at Rothamsted in 1853, using a copper funnel rain gauge (5 inch / 12.7 cm diameter) and measured using a graduated cylinder. Data was collected daily, manually, until 2004 and since then by Automatic Weather Station using a standard protocol. Since 2004 it has been measured using an electronic tipping bucket rain gauge (10 inch / 25.4cm diameter), ARG100, calibrated to tip at 0.2mm (which has since become the minimum amount of rain that can be recorded). The rain gauge is placed within a 30cm deep 1.5m radius turf wall, retained by brick, to reduce wind eddies that may potentially blow rain out of the gauges. Since Sept 9th 2020 it has been recorded with an SBS500 tipping bucket rain gauge, funnel diameter 25.2cm and calibrated to tip at 0.2mm, manufactured by Environmental Measurements Ltd (EML), supplied and calibrated by Campbell Scientific. It is no longer sited within the turf wall, as the aerodynamics of the gauge means that it should not be affected by wind eddies. From December 10th 2003 to 8th Sept 2020 it was measured by an electronic tipping bucket rain gauge of 25.4cm (10 inch) diameter, ARG100 (manufactured by EML, supplied and calibrated by Campbell Scientific), calibrated to tip at 0.2mm, within the original turf wall. The old 5 inch manual copper rain gauge is still used to manually measure precipitation fallen as snow when the tipping bucket rain gauge is blocked with snow or ice. 

NOTE 1. There is a slight discrepancy in the amount of rain measured by the ARG100 rain gauge between 10/12/2003 and 09/09/2020 a correction factor is advised for these data.

NOTE 2. Rain recording started at Rothamsted in March 1853 and thus the total for that year is for 10 months March-December.
description: An Excel file containing monthly and annual total rainfall for each year, and charts of these data.
description: Location: Rothamsted Meteorological Station, Harpenden, Hertfordshire, England 51.82 N 0.37 W 128 m asl. 

Over time, there have been changes to the rain gauges used:
06/02/1853 – 1948; 5 inch (12.7cm) diameter (cylindrical gauge), at ground level.
1948 – 11/12/2003; MK2 5 inch (12.7cm) diameter (cylindrical gauge), in turf wall.
11/12/2003 – 09/09/2020; ARG100 10 inch (25.4cm) (tipping bucket, hourglass), in turf wall.
09/09/2020 – present; SBS500 9.9 inch (25.1cm) (tipping bucket, hourglass), at ground level.
description: The annual summary data contained in this spreadsheet are derived from daily data measured at Rothamsted Meteorological Station, Harpenden. Total annual data are derived from the monthly data determined from daily data using MS Excel. Verification includes checks for instrument errors, for missing data and outliers. The original raw daily data is available, after registering, from the e-RA database. Please contact the e-RA Curators for an access password and further details.

We thank the many weather recorders who have contributed to the collection of these data over the years;
Dave Yeoman (past)
John Croft - Met Observer (past)
Bob Norrish (past)
Denise Legg (past)
Chris Hall (past)
Paul Hargreaves (past)
Tim Hall (1990s)
Helen Martin (past)
Alan Thornhill (past)
Aiming Qi (past)
Phil Styles (past)
Andrew Hunt (past)