Most listings are in the $20's per square foot per year. The Modesto region is seeing a an increase in rates. In the last 3 months, the median rate rose $3 per sqft per year. That's a 17% increase in rent.
In the last 90 days, 29 listings have been made available, which means leases most likley are going fast. You'll want to be prepared to make an offer immediately. About 3% of the available space in the Modesto are subleases, so you will probably have to consider a longer term lease. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,860 sqft. Most properties in this region are around 1 floors. Most buildings in this market were built in 1981 and are Class B.