Weather during the survey

The following comments are generalized and refer to the county as a whole. The two large estuaries have a major influence on the weather of Wirral and much of northern Cheshire, and the eastern hills tend to be colder and wetter than the rest of the area. These brief summaries reflect the influence of the weather during the Atlas period on the birds and on observers' ability to record them.

The three breeding seasons of this Atlas, 2004 to 2006, experienced a variety of weather, as is normal in Britain. All three years were warmer and sunnier than the long-term average. In 2004, changeable April weather allowed most migrants to arrive on or around the normal schedule but the early individuals had to endure some cold and rainy days. May and June were mostly warm and dry, good for most birds and for recording, until gales from late June heralded a wet July and a curtailed breeding season for many species, with relatively few late broods. 2005 was the most equable of the three breeding seasons, with temperatures somewhat above the long-term mean, sunshine about normal and less rain than average. April 2005 was unpredictable, wet and cool at times until the last week of the month, delaying early Atlas recording, but the period from May to July was about as settled as it gets in this country, mostly dry with average temperatures, before August was again changeable and cool. The 2006 breeding season started late, with the coldest March for ten years and a changeable April followed by the wettest May for twenty years. June and July were unusually hot and settled, with the spell broken early in August and another rainy month to end any late breeding attempts for most species.

All three winters of our Atlas were typical of recent times, with rapidly changing weather, often windy and generally mild, with no freezing spells severe enough to force birds to move. During winter 2004/05 there were days of gales, torrential rain and snow, but none of them lasting for long. The hours of sunshine were above normal, as were winter temperatures, and there was not a single day where the temperature stayed below freezing. Drought in southern England dominated the London-based media but rainfall elsewhere, including in northwest England, was average. Winter 2005/06 was the coldest and driest of the three winters, although average temperatures were still above the long-term mean. Our winter Atlas period from mid-November started with overnight frosts before settling to our usual pattern of depressions coming off the Atlantic (warm, windy and wet) alternating with high pressure (cold, calm and dry) for the rest of the winter. Winter 2006/07 was extraordinarily warm (mean temperature for the region 2.3°C above the 1961–90 average) and wet (half as much rainfall again as the long-term average). Unprecedented combinations of winds in the first weeks of our final winter period inhibited some Atlas recording but drove several species of seabird out of the Bay of Biscay and unexpectedly onto the pages of this Atlas.

This summary has been based on the published data from the UK Meteorological Office, especially their seasonal figures for north-west England and North Wales ( and the Central England Temperature record (, with local information taken from the CWBRs, with thanks to Tony Broome and Hugh Pulsford.