It seems too good to be true — there could be perfect weather just in time for the summer solstice tomorrow, the first week of Wimbledon starting on Monday and a mud-free Glastonbury music festival from Wednesday onwards. Blue skies, warm sunshine, light breezes and steadily rising temperatures are all expected to make this a week to head outdoors. Not only that, but temperatures could reach their highest of the year so far, with Met Office forecasters predicting a chance of highs breaking the 30C (86F) level on Wednesday.

After this month’s big downpours and thunderstorms, it looked like we were heading for a repeat performance of the washout summers of 2007 and last year. But instead of the high-level jet winds that swept barrages of depressions over Britain for the past two summers, the coming week’s fine weather is courtesy of an offshoot of the Azores High-Pressure system. This anticyclone usually dominates the sub-tropical seas of the Atlantic around the Azores, and when it thrusts a finger towards Britain brings fine summer weather. Exactly where the Azores High sits over Britain will set how hot it gets — if it lies out towards Scandinavia, hot air could sweep across from Europe and send temperatures soaring.

Of course, the good weather cannot last for long and there are early signs that it could come to a soggy end by next weekend, although this is still too far off for forecasters to make confident predictions. But then the chances of a completely dry Wimbledon are always extremely remote — on average it happens once every 20 years. At least this year the retractable roof over Centre Court will protect against any showers.

The settled weather is predicted to arrive as we head towards the summer solstice, when the Sun reaches its highest point in the sky in the northern hemisphere and we bask in the longest hours of daylight. This also marks something of a turning point in the weather calendar. The first three weeks of June are often plagued by the European Monsoon, when Atlantic winds loaded with rain clouds often make a wet start to summer, which is what has happened so far this month. But by the time of the solstice, conditions often calm down as high pressure builds up. In olden days this turning point was looked for on Midsummer’s Day, on June 24, but if it turned wet that day it signalled more bad weather for the rest of the summer: “June just rains and never stops, Thirty days and spoils the crops.”

Whether the good spell signals a fine summer remains to be seen, but the Met Office remains fairly confident of the long-range forecast for a barbecue summer, with plenty of decent spells of sunshine, interspersed with a few showers.