Autumn 2018: what your records show
Judith Garforth, 27/06/2019
Nature’s Calendar is a phenology project and when you add a record to the Nature’s Calendar website, it gets saved straight into the UK phenology database. Twice a year we analyse all the records added to the database during the previous six months, to find out how nature has responded to the weather during that time.
We’ve just finished analysing all your records from July to December 2018, and here is a summary of what we’ve found out:
We don’t collect our own weather data, but use information from the Met Office to help put our nature records into context. If you can’t remember what the weather was like last year, here’s a quick reminder:
- Overall, autumn 2018 was a largely warm season.
- July, which was the second warmest since 1910, and was also a dry month.
- There were considerable regional differences in rainfall during the rest of the season. North West Scotland was particularly wet in September and similarly Devon in November.
- July and October were sunny months.
We calculated the UK average date for each species and event in autumn 2018 and compared it to the UK average date in the benchmark year of 2007*.
There was no overall pattern to the dates in autumn 2018; some species and events were earlier than then benchmark year, whereas others were later. This is in contract to recent autumns such as 2017 when most species and events were recorded earlier than during the benchmark year and 2016 when most autumn species and events were recorded later than during the benchmark year.
Swifts were the first of the migratory birds to leave the UK as usual, with an average last recorded date of 8 August. House martins and swallows departed over a month later, in mid-September.
The average first recorded dates for fieldfares and redwings arriving in the UK were the 1 and 4 November; these dates are eight and nine days later than during the benchmark year.
Trees and shrubs
The first tinting of leaves on trees and shrubs started in September. Horse chestnut had the earliest average first tint date (2 September) most probably due to leaves changing colour early due to the leaf miner infestation.
First tinting of elder (13 September) and rowan (17 September) came next, and first tinting of ash and oak was seen later in the season. The average first tint date for oak (2 October) was a month later than for horse chestnut.
First tinting of ash and elder was a week earlier than the benchmark year, whereas first tinting of pedunculate oak was a week later than the benchmark year.
The average date of the last lawn cut was 27 October, which is three days earlier than during the benchmark year, although many of you found it necessary to mow your lawn all winter.
A huge thank you to everyone that submitted a record from July to December last year and made this analysis possible. We really appreciate all the time and effort you put into recording.
Your records contribute to a powerful dataset that helps scientists to understand nature’s response to changes in the environment; so please recording!
*Ideally, we’d compare to a long-term average, but because the project is only 19 years old, we don’t have enough years of data to do this yet. Instead, we chose 2007 as a benchmark year because the mean monthly temperatures during autumn 2007 were similar to the 1961-90 30-year averages.