Pembrokeshire was set up to take over the functions of the Pembrokeshire Quarter Sessions. This and the administrative county of Pembrokeshire were abolished under the Local Government Act 1972, with Pembrokeshire forming two districts of the new county of Dyfed: South Pembrokeshire and Preseli – the split being made at the request of local authorities in the area. In 1996, under the Local Government (Wales) Act 1994, the county of Dyfed was broken up into its constituent parts, and Pembrokeshire has been a unitary authority since then. In 2017 Pembrokeshire County Council had 60 members and no political party in overall
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