On average, listings lease in the $30's per square foot per year. The Monrovia region is going through a an increase in rates. In the last 3 months, the median rate rose $34 per sqft per year.
Compared to the rest of the Metropolitan Los Angeles market, the Monrovia submarket has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 5 listings have been listed, which means leases might be going fast. You'll want to be prepared to tour spaces as quick as possible. About 120% of the office spaces in the Monrovia are subleases, so you might be able to snag a great spot on a short term. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
Even though the median size is 3,600 sqft, there are still 0 new listings below 2,000 sqft. Most buildings in this market are approximately 2 floors. Most buildings in this region were built in 1982 and are Class B.