Hot spring, wet spring

The two distinctly non-average months of March and April were heavily influenced by the position of the jet-stream, as shown in the illustration opposite.

In the depths of winter, this fast moving ribbon of air in the high atmosphere usually flows across the south of England, steering low pressure systems across the Atlantic towards the UK.

In the height of summer, the jet stream flows across northern Scotland, deflecting unsettled weather to the north of the UK.

In March, the jet stream was heading north and brought settled and unusually warm weather, but a southerly shift in the jet stream's track brought unsettled weather for April.

March was the third warmest and the fifth driest on record for the UK with 36.4 mm of rain compared to the average 95.9 mm. Dry conditions meant that the Environment Agency declared drought conditions, while water companies across southern and eastern England introduced hosepipe bans.

The reason it was so unseasonably warm early in the year was mainly due to the air flow above the UK. With high pressure, we had settled conditions with light winds and sunshine. During the daytime, the sun provided plenty of warmth and the light south to south-easterly winds drew more warm air towards us from continental Europe.

April was in stark contrast to March. Not only was it cooler on average than March - the first time this has happened since 1998 - it was the wettest April in the UK for more than a century. While there was snow in some areas just before Easter, the weather was mainly dry and bright for the London Marathon.

Even with the wettest April on record, after two dry winters, parts of the UK remained in drought. Much of the rainfall was in the south of the UK, with England having more rain than Scotland. Despite the rain, sunshine during April was not far off average.

Large parts of the UK had wet and windy conditions over the weekend of 29 April. Winds gusted over 70 mph in exposed locations. The strongest gust at a non-mountain site was 71 mph at Mumbles Head in West Glamorgan.

Cold weather for the early May Bank Holiday weekend arrived after a particularly wet and windy weekend to finish April. Severe Weather Warnings were in place for Monday 30 April and Tuesday 1 May for many parts of the UK as persistent heavy rainfall was widespread.

Some areas had much of their normal monthly average rainfall within 24 hours. The joint Environment Agency and Met Office Flood Forecasting Centre issued many Flood Warnings and Alerts. The heaviest rainfall was in southern England causing localised flooding, while other parts of the country, particularly the far north, saw little or no rain.

A few snow showers in early May seemed out of context for the time of year. However, while it's not completely normal, it's not completely unusual either, as it snowed in May last year and in 2010. Weather is often in the news but weather forecasters hit the headlines in May after His Royal Highness the Prince of Wales and the Duchess of Cornwall delivered the Met Office weather forecast on the BBC during a tour of BBC Scotland's Glasgow headquarters. It's not the first time the Prince has had a close-up view of the Met Office's world- leading forecast science, after visiting our Exeter HQ in 2009.

The end of May was dry, warm with blue sky and almost unbroken sunshine. Temperatures reached 28 °C in places, with the warmest day of the year so far on Friday 25 May. Even with variable cloud cover, UV levels were high so we encouraged people to stay up-to-date with our UV forecasts to avoid sunburn.

Throughout May, we were busy providing weather forecasts to the London Organising Committee of the Olympic Games and Paralympic Games (LOCOG) as well as local and national government for the Torch Relay, Olympic and Paralympic Games to support event organisers, competing athletes and visitors and spectators.