It shares borders with the city of Rocklin and the Census-Designated Places Penryn and Granite Bay.

[9] The railroad and Post Office found that Pino was confused with the town of Reno, hence the name change to Loomis.

[9] In the early part of the 20th century, Loomis was the second largest fruit-shipping station in Placer County, Newcastle California, just 6 mi (9.7 km) east of Loomis, was considered the largest.

The Town was in danger of being annexed by its neighbor Rocklin and the residents voted to incorporate to preserve local control, partly on the issue of preserving the "small town" character and historic structures such as the High Hand and Blue Goose fruit packing sheds which sit between Taylor Road (a segment of historic Highway 40) and the Union Pacific Railroad tracks.

According to the United States Census Bureau, the town has a total area of 7.27 square miles (18.8 km2), all land.

Stream drainages in Loomis are Antelope Creek and Secret Ravine.

Loomis has a hot-summer Mediterranean climate (Köppen Csa) that is characterized by cool, wet winters and hot, dry summers.

As with the rest of cities in the northern Central Valley, Loomis has hot summers with sparse rainfall and abundant sunshine.

Average daily high temperatures range from 53 °F (12 °C) in January to 94 °F (34 °C) in July with August remaining nearly as hot.

The biggest event in Loomis is the Eggplant Festival which offers entertainment, arts and crafts, food, and children's activities.

Smaller festivities include the Loomis Friday Night Family Fest during summer and the Cowpoke Fall Gathering.

[16] As of May 2019 Loomis was estimated to have a civilian workforce of 3,793 representing 59% of the total population.

Placer County Transit provides weekday commuter service to/from the Penryn Park and Ride to/from Downtown Sacramento.