This is how Sheffield's weather station has evolved over time and why it plays an important role in recording climate change
From the fatal floods of 2007 to the record-breaking temperatures of 35.1C the city basked in in 2019, the Weston Park weather station has recorded every minor and major weather event that has taken place in Sheffield for the last 139 years.
Despite world wars, pandemics and recessions, the weather station has never experienced a break in recording since it was set up by the curator of Weston Park Museum, Elijah Howarth, in September 1882.
That, coupled with the fact Weston’s Park’s is one of the longest-running weather stations in the country, means it is an incredibly vital, and significant, resource in measuring climate change.
"We can’t say why the climate is changing, but we can say that it is changing and it is getting warmer. We’re getting more intense periods of rainfall, and things like that,” said Alistair McLean who is the fifth custodian of the weather station, which falls under his remit as the Curator of Natural Science at the Sheffield Museums Trust.
He confirms this summer has not been an extreme one, and quickly brings up data which reveals it has been the 20th driest summer since Sheffield’s records began; and the 11th warmest on record, with an average temperature of 16.8C, compared with the summer average of 15.5C.
While this summer was hotter than average, the temperature failed to reach 30C for the first time since 2014.
This is in stark contrast to the summers of 2019 and 2020, when not only did Sheffield sizzle in the sun with temperatures soaring beyond 33C, but on July 27, 2019 the city recorded its highest ever temperature of 35.1C.
2019 was also a record-breaking year in terms of rainfall.
It was officially the wettest year the city has ever seen with 1,176 millilitres of rain falling over Sheffield during the course of the year.
Just under a fifth of 2019’s rainfall occurred in November, during which Sheffield experienced its worst flooding for years following torrential rain on November 7, leaving several parts of the city under water and leading to shoppers being stranded at Meadowhall shopping centre.
2020 was also a particularly wet year, when Weston Park weather station recorded a total of 997 millilitres of rainfall.
Autumn can be a game changer
Alistair says it is currently too early to predict whether this autumn will also be a wash out, but notes that this September has already been wetter than that of 2019.
He adds that autumn is usually a game changer when it comes to record-breaking weather.
“It just goes to show that at this point in the year we could go on to have a really dry autumn, and have the driest year on record. But if it goes on to be very wet we could be looking at the wettest year so far. Right now, we’re on the damper side of average, but not significantly so, so it could go either way,” said Alistair.
The changes brought about through modernisation
While it took Alistair a matter of seconds to bring up the data used above, the task of compiling such figures used to be far more arduous and would take much longer.
Alistair, who took on the role of weather station custodian in 2010, recalls previously having to scroll through numerous pages of a spreadsheet to bring up figures, and as a result, monthly weather summaries used to take up to half a day to compile.
And that was after the figures had been digitised, prior to that, everything had to be recorded in paper ledgers.
That is just one of a myriad of ways in which the weather station has been modernised during Alistair’s tenure.
He also remembers having to go down to the weather box in Weston Park every morning at 9am to record temperatures from the mercury themometers previously used, and would also have to manually work out humidity.
Alistair explains: “We would be out there in all weathers, 365 days a year. It had to be a huge team effort, because you couldn’t have one member of staff doing all of that, 365 days a year.”
He added: “When I first started, the weather station was operating in the same way it had been since its inception in September 1882.”
Today, everything is automated, including the way in which temperature and rainfall is measured.
"We had to gauge the rainfall with a measuring cylinder...the way it used to work was we had a storage gauge, a funnel, buried in the ground. It funnels the rainfall and pours it into a measuring cylinder,” said Alistair, adding that they would then measure the amount of water in the cyclinder.
He continued: "We now use a tipping bucket, but it’s not as sophisticated as it sounds. It’s a relatively old invention. It pours the rain fall into a pair of buckets, and when it reaches a certain amount on one side it causes it to pivot. It pours away the water, and begins to fill the other bucket, and fills it to a certain point and so on….0.2 mililitres of rain causes it to pivot...so we just measure the pivots. It’s a bit like a seesaw, with rain being funnelled on to one end or the other.”
Another curious method previously used to measure weather events is the Campbell-Stokes recorder, which uses a glass ball and a piece of cardboard to record the number of hours of sunshine on a given day.
“It directs rays of sunshine on to a piece of cardboard, as the sun moves across the sky, burn marks move along the cardboard, and we would measure the burn marks,” said Alistair, adding they would have to alter the size of the cardboard used as the seasons changed.
The Campbell-Stokes recorder was used by the Weston Park weather station until 2006, when they changed to a far more modern electronic method.
The advent of hourly recording
The modernisation of the equipment used by the weather station, which is ‘run on a shoestring’ has also meant that instead of only adding daily weather readings to their database, they are now able to add hourly ones.
Unsurprisingly, this has had a huge impact on the amount of recordings held on their database, which covers every reading taken from 1882 through to today.
The weather station submitted daily readings from 1882 until 2009, and during that time they added a total of 50,771 entries to their database.
They have submitted daily readings from 2009 through to the present day, and at the time of writing had a recorded a total of 107,542, more than doubling the amount taken over a 128-year period in just 12 years.
One weather recording which has been impacted by the evolution and growth of Sheffield is that of wind speeds.
Since 1896, Sheffield’s wind speeds have been measured using a mast located on top of the museum; but Alistair says the ‘problem’ with their contemporary recordings is the way in which the area around Weston Park Museum has ‘built up’ over time, affecting the accuracy of their wind speed data.
"On the one hand, we have got a very useful comparative reading tool, but because the Arts Tower is next door, we can’t definitively say that the readings are as accurate as we’d like them to be.
"While the rest of our data is of a Met Office standard, the wind speed isn’t, but we still record it,” Alistair explained.
During a bad storm last year, the weather station’s mast recorded wind speeds of 40 knots, but Alistair did not believe that to be accurate so put out an appeal out on Twitter to see how that compared with the speeds recorded by others in the city.
A representative from BAM, the firm responsible for the construction of the social sciences building on the site of a former reservoir located between nearby Northumberland Road and Whitham Road, got in touch to say they had also recorded the wind speeds using a mast on top of their crane.
Just as Alistair suspected, the weather station’s reading was not quite right, with the BAM mast recording speeds of 70 knots.
Weather station custodian
Alistair is only the fifth person to hold the role of weather custodian since 1882, and describes the responsibility as a ‘privilege’; but admits it is also a ‘worry’ because he does not want to be the person who jepoardises, or puts an end to, the continuous recording.
Thankfully, the Met Office installed a separate weather station at Weston Park in 2013, which means that in the event of any issues with recording for either party, there is a back-up set of data that should allow them to fill any gaps in their ledger.
The most recent occurence took place in the middle of August this year, following a heavy rainfall.
Alistair and the team noticed the Weston Park weather station had stopped recording, and when he went to investigate he found the rain gauge had been blocked by a slug.
Alistair’s role as curator of natural science involves a plethora of other responsibilities including putting on exhibitions, and is currently in the process of putting together a ‘small display’ at Weston Park Museum on the impact the use of plastic has on wildlife and marine life, something that has particularly affected the South Atlantic and Pacific oceans.
Alistair described how the display, which he hopes will be available to view from September 17, is smaller than the ones you might be used to seeing at the museum, in a bid to use fewer materials, including plastic, that are damaging to the environment.
How you can find up-to-date weather recordings from Weston Park’s station
In years gone by, the weather station team would post the weather readings recorded on the Museum’s noticeboard, but today you can find daily updates online via the weather station’s Twitter account at: https://twitter.com/WPWeather
The weather station also offers a subscription service to members of the public, through which those signed up receive weather data on a monthly basis.
It costs £15 and all of the money raised through the service is used to help pay for the maintenance of the weather station, the cost of which runs into thousands of pounds every year.
For more information please visit: https://www.museums-sheffield.org.uk/museums/weston-park/planning-a-visit/weston-park-weather-station