Pembrokeshire plays in WRU Division One West. Triathlon event "Ironman Wales" has been held in Pembrokeshire since 2011, contributing £3.7 million to the local economy, and the county committed in 2017 to host the event for a further five years. "Ras Beca", a mixed road, fell and cross country race attracting UK-wide competitors, has been held in the Preseli Hills annually since 1977. The record of 32 minutes 5 seconds has stood since 1995. Pembrokeshire Harriers athletics club was formed in 2001 by the amalgamation of Cleddau Athletic Club (established 1970) and Preseli Harriers (1989) and is based in Haverfordwest. The
Pembrokeshire to its proximity to the relatively warm Atlantic Ocean. Inland, average temperatures tend to fall 0.5 °C for each 100 metres increase in height. The air pollution rating of Pembrokeshire is "Good", the lowest rating. The rocks in the county were formed between 600 and 290 million years ago. More recent rock formations were eroded when sea levels rose 80 million years ago, at the end of the Cretaceous Period. Around 60 million years ago, the Pembrokeshire landmass emerged through a combination of uplift and falling sea levels; the youngest rocks, from the Carboniferous Period, contain the Pembrokeshire Coalfield. The