Reliable Pools, Inc. suggests fiberglass pools for the Bloomington-Normal, IL weather because they are known for their durability and ability to withstand various weather conditions, including colder climates. Fiberglass pools are designed to be structurally stable, exhibiting less expansion and contraction due to heat or cold compared to other pool materials like concrete and vinyl. Additionally, fiberglass pools are chemically stable, making them resistant to UV rays, pool cleaners, chlorine, and other pool sanitizers, ensuring longevity and low maintenance in different weather environments.