Urban Weather often can be influenced by various factors, one being huge columns of heat ascending upwards, especially during summer (heat islands). Smog can also be a common feature when summer heatwaves arrive, causing problems for some people, especially those with breathing problems.

So, city and country weather conditions are very often different. Cities are built with materials that do not absorb water, therefore when precipitation descends from the heavens, most of the water drains away before it can evaporate and condense again into clouds. Drainage and sewerage systems cannot cope with the vast amount of water which now falls in some storms, flash flooding and raw sewage spills out, effecting some locations.

Heat islands in summer when the air is unstable, can provide developing thunderstorms with plentiful heat source and energy to produce super-thunderstorms. During the day, roads and buildings are heated up by the Sun. At night they cool, releasing heat and warming the city air. At night the relative humidity in a city can be as much as 35% lower than in the near countryside. Buildings deflect the wind, making complicated patterns and currents as the wind eddies around them. When the wind blows at right angles to a building, the air will form those eddies around the buildings with surprising results.

So, town and city centre's are often warmer, with a different feel to it's climate than that of the near countryside. Due to that extra heat, winter fog will be rare in the city, that vast bubble of warmer air keeping fog at bay.

Next Week......Measuring the wind.

The answer to last week's question......during the day.This week's question.....is the heat effect coming from a city called:

A/ Heat Surge.

B/ Heat Island.Glossary of Common Weather Terms:

Glaze Ice: Rain which instantly freezes on contact with the ground causing dangerous conditions both on road and under foot.Weather for period Monday 18th June-Friday 22nd June.Another slow moving low pressure system moving in off the Atlantic from the south-west.

The week will be humid with winds in from between south-west/south/south-east light but squally beneath storms. All parts can expect heavy slow moving cloudbursts/thunderstorms at times, short lived drier brighter spells between. 1-2 inches of rainfall may occur in some locations giving local flooding. Humid conditions throughout.

Maximum temperature 19-21c 66-70f.Minimum temperature 13-15c 55-59f.Last Week's Observations (Monday-Friday)Highest day temperature......24.0c 75f on Monday 11th June.Lowest night temperature.....11.9c 54f on Tuesday 12th June.Wettest day....30.2 mm from thunderstorms on Thursday 14th June.