England is known as having a pretty lousy climate that is hard to predict. Even late into the spring and summer it can be cold and rainy, and this can ruin a lot of vacations. However, there are some things to keep in mind. First, because of the trade winds and the flow of the Atlantic Ocean, England, and most of western Europe for that matter, has much milder winters than in the United States. This isn't to say that there is no snow or extreme cold, but it is much more hospitable to visit during March, than it is to visit New York. It's best to always have some pants and at least a sweatshirt on you when you visit England, and Bristol is no exception. Located on the coast, it can get quite cold. The sea breeze blows in and the temperature can be about 5-10 degrees fahrenheit colder than it is further inland. The best time of year to visit Bristol is during the late spring and early-mid summer months. This is give you your best chance of having consistent good weather, but again, it is hard to predict the weather in England. If you do encounter some bad weather in England, at least you can be assured that you got a real taste of the country.

Here is the link to Bristol Weather : BBC Five Day Forecast and The Weather Channel website