Quick answer: May is the best weather month in Cornwall, and it is not close. It is the sunniest month of the year, the driest month of the year and, on the north coast, the month with the fewest wet days. There is no frost. Daylight passes sixteen hours. And in 2027 it carries two of the great British folk festivals on consecutive Saturdays — Padstow’s Obby Oss on 1 May, running into a bank holiday, and Helston’s Flora Day on 8 May.
If someone asks when to come to Cornwall and they do not need school holidays, the answer is May. The statistics are unambiguous and the calendar in 2027 is exceptional. This follows Cornwall in April, and the full-year picture is in our weather guide.
Table of Contents
- May weather at a glance
- The sea, and the first basking sharks
- Sixteen hours of daylight
- Obby Oss, Saturday 1 May 2027
- Flora Day, Saturday 8 May 2027
- When to come, if you want it quiet
- Practical notes
- FAQ
- References and resources
May weather at a glance
| Camborne (west) | St Mawgan (north coast) | |
|---|---|---|
| Average daily high | 14.5°C | 15.1°C |
| Average nightly low | 8.8°C | 8.9°C |
| Rainfall | 61mm | 58mm |
| Days with 1mm+ of rain | about 10 | about 10 |
| Sunshine | 216 hours | 224 hours |
| Nights with air frost | 0 | 0 |
Two outright annual records and a near-third, all checkable:
- The sunniest month of the year. 216 hours at Camborne and 224 at St Mawgan — ahead of June (215 and 220) and comfortably ahead of July (199 and 207). About seven hours of sunshine a day.
- The driest month of the year. 61mm at Camborne, 58mm at St Mawgan. Half of what falls in January.
- Under ten wet days. 9.8 days with a millimetre or more of rain at St Mawgan, the fewest of any month there; Camborne’s 9.8 is a shade behind June, which edges it at 9.5.
People assume high summer is Cornwall’s best weather. It isn’t. July and August are warmer, but they are wetter, cloudier and far busier. May is the month that quietly wins on everything except air temperature — and at 14.5–15.1°C in the day, with no frost at night, it is perfectly comfortable for walking, which is what Cornwall is best at.
The sea, and the first basking sharks
The water reaches about 11.2°C at Newlyn on the long-run coastal record, up more than a degree and a half on April. That is still cold — below the 15°C threshold at which cold-water shock stops being a risk — but it is the point at which a short swim without a wetsuit becomes a reasonable thing to do rather than an ordeal.
May is also when basking sharks return to Cornish water, the second-largest fish in the world, feeding on plankton along the south west coast from May through to October. They are the headline, but May is broadly the month the sea comes alive again. Our wildlife calendar covers the whole year, and the cold-water guide covers swimming safely.
Lifeguard cover expands through May towards the summer pattern, but the 2027 schedule was not published when we wrote this — check the RNLI’s beach finder for the beach you want rather than assuming.
Sixteen hours of daylight
| Date | Sunrise | Sunset | Day length |
|---|---|---|---|
| 1 May | 05:59 | 20:40 | 14h 40m |
| 15 May | 05:37 | 21:01 | 15h 24m |
| 31 May | 05:19 | 21:21 | 16h 02m |
A gain of one hour twenty-two minutes across the month, and the point at which the long Cornish evening properly arrives. By the end of May the sun is still up at twenty past nine and the light lingers for a good half hour after that. It changes what a day can hold: a full day out and then a beach or a coast path walk afterwards.
Obby Oss, Saturday 1 May 2027
Padstow’s May Day is one of the oldest and strangest surviving folk customs in Britain, and in 2027 it falls on a Saturday, running into the Early May bank holiday on Monday 3 May. That combination has not happened for years and it will fill the town.
It begins at midnight on 30 April, when the town gathers outside the Golden Lion Inn to sing the Night Song. On the day itself two processions move through streets dressed with greenery, each led by an ‘Obby ‘Oss — the Old Oss and the Blue Ribbon Oss — a dancer under a mask and a black frame-hung cape, driven on by a Teaser. Late in the evening the two Osses meet at the maypole before returning to their stables, where the crowd sings of the Oss’s death until its resurrection the following May Eve.
It is not a show put on for visitors. It is a town doing something it has always done, and it is genuinely overwhelming in the best way — the drums, the accordions and several thousand people singing the same song all day.
If you are going: book accommodation months ahead, expect Padstow to be full, and consider staying elsewhere and travelling in. Parking is hopeless. 2027 details were not published when we wrote this.
Flora Day, Saturday 8 May 2027
One week later, Helston does something completely different and just as old. Flora Day falls on 8 May every year, moving only if that date lands on a Sunday or a Monday — and in 2027, 8 May is a Saturday, so it stays put.
The day runs on dances. The big bass drum strikes the first beat at seven in the morning, and couples dance through the streets in sets through the day, entering selected houses and shops — the point of which is to drive the darkness of winter out of the buildings and let the spring in. The town is dressed in greenery and flowers throughout.
Between the dances comes the Hal-an-Tow, a pageant in which the characters sing Helston’s history: the Spanish Armada, St George, and the fight between St Michael and the devil. It is the older and wilder part of the day. The background to both festivals is in The Story of Cornwall, and the Cornish you will hear is covered in our Cornish language guide.
Two of Britain’s great calendar customs, in the same county, on consecutive Saturdays. If you have any interest in folk tradition, the first ten days of May 2027 are the trip of the year.
When to come, if you want it quiet
May 2027 has an unusually clear shape, because the bank holidays sit at either end and the Cornish half term is at the very back of the month.
- Sat 1 – Mon 3 May: Obby Oss into the Early May bank holiday. Busy, especially the north coast.
- Sat 8 May: Flora Day. Helston and the Lizard busy for the day.
- Mon 10 – Fri 28 May: term time, no bank holiday, best weather of the year. This is the window.
- Mon 31 May – Fri 4 June: Cornish half term, and the Spring bank holiday on the 31st. Busy, and prices rise.
Those three middle weeks are, on the numbers, the best combination of weather and quiet that Cornwall offers all year. Everything is open, the days are nearly at their longest, and the roads are empty by summer standards. Our where to stay guide covers where to base yourself, and the festivals guide has the rest of the calendar.
Practical notes
- Book now if you want the festivals. Obby Oss on a Saturday into a bank holiday is the busiest Padstow gets. Accommodation for the first weekend of May 2027 will go early.
- Pack lighter, but still pack a shell. Ten wet days is the fewest of any month, but it is still ten.
- Sun cream, properly. Seven hours of sunshine a day and a sea breeze that disguises how much you are getting is how people burn in May.
- A wetsuit is still worth having at 11°C, though a short swim without one is survivable by the end of the month.
- Bluebells are still out in the first half of the month — see our woodland walks guide.
- June follows with the longest days of the year and the Royal Cornwall Show: Cornwall in June.
FAQ
Q: What is the weather like in Cornwall in May?
A: Highs of about 14.5–15°C and lows near 9°C, with 58–61mm of rain over about ten days and 216–224 hours of sunshine, roughly seven hours a day. There is no air frost in May at either of Cornwall’s long-running weather stations.
Q: Is May the best month to visit Cornwall?
A: On the weather statistics, yes. May is the sunniest month of the year, the driest month of the year and the month with the fewest wet days, at both Camborne and St Mawgan. July and August are warmer but wetter, cloudier and much busier.
Q: When is Obby Oss in Padstow in 2027?
A: Saturday 1 May 2027. The festival is always on 1 May and begins at midnight on 30 April with the Night Song outside the Golden Lion Inn. In 2027 it runs into the Early May bank holiday on Monday 3 May, so Padstow will be exceptionally busy.
Q: When is Helston Flora Day in 2027?
A: Saturday 8 May 2027. Flora Day is held on 8 May each year unless that date falls on a Sunday or Monday, when it moves to the preceding Saturday. In 2027 the 8th is a Saturday, so it stays on the day.
Q: When is the quietest time in Cornwall in May?
A: Roughly 10 to 28 May 2027. The bank holidays fall on 3 and 31 May, the two festivals are on the first and second Saturdays, and Cornwall’s half term runs 31 May to 4 June, leaving the middle three weeks as term time with the best weather of the year.
Q: Can you swim in the sea in Cornwall in May?
A: It is about 11.2°C, still below the 15°C cold-water threshold but much improved on April. A short swim without a wetsuit becomes reasonable by late May. Check the RNLI beach finder for lifeguard cover, which expands through the month.
References and resources
- Met Office — Camborne long-term averages: www.metoffice.gov.uk
- Met Office — St Mawgan long-term averages: www.metoffice.gov.uk
- Cefas — sea temperature records, Newlyn: www.cefas.co.uk
- Cornwall Council — school term dates: www.cornwall.gov.uk
- gov.uk — UK bank holidays: www.gov.uk
- Helston Flora Day: helstonfloraday.org.uk
- RNLI — find a lifeguarded beach: rnli.org
