Moving in or out mid-month in Rapid City? Enter your monthly rent and date to calculate exactly what you owe for a partial month, with South Dakota deposit and notice rules for 2026.
Last updated: May 2026 · Data: MIT Living Wage Calculator, C2ER, U.S. Census, BLS, IRS, state and city sources
Prorated rent is what you pay for a partial month when you move in or out on a day other than the first. With average Rapid City rent near $1,000/month, the standard method divides monthly rent by the days in the month and multiplies by days occupied. South Dakota caps the security deposit at one month's rent (with more allowed by agreement for special conditions) and requires the landlord to return it within two weeks of move-out, or within 45 days with an itemized statement of any deductions. A one-month written notice generally ends a month-to-month tenancy.
| Rule (South Dakota) | Detail |
|---|---|
| Average 1-bedroom rent | $1,000/month |
| Average 2-bedroom rent | $1,250/month |
| Security deposit limit | one month's rent (more by agreement for special conditions) |
| Deposit return deadline | two weeks (45 days with an itemized list) after move-out |
| Month-to-month notice | one month (month-to-month) written notice |
| Standard proration formula | Rent ÷ days in month × days occupied |
Example: rent is $1,000, move-in is the 10th of a 30-day month, so 21 days remain. Prorated rent is ($1,000 ÷ 30) × 21 = $700.
Rapid City is the gateway to the Black Hills and Mount Rushmore, with an economy built on tourism, Ellsworth Air Force Base and its bomber mission, healthcare serving a wide region, and retail trade for the western Dakotas and eastern Wyoming.
| Local Metric | Rapid City (2026 estimate) |
|---|---|
| Metro population | 78,000 |
| County / jurisdiction | Pennington County |
| Cost of living index (US avg = 100) | 89 |
| MIT living wage, single adult | $19.00/hour |
| MIT living wage, one earner supporting a family of four | $38.50/hour |
| Applicable minimum wage | $11.20/hour |
| Average rent, 1-bedroom | $1,000/month |
| Average rent, 2-bedroom | $1,250/month |
| Median home price | $320,000 |
| Median household income | $60,000/year |
| Combined sales tax rate | 6.2% |
| Effective property tax rate | 1.1% of value/year |
Local figures are 2026 estimates compiled from the MIT Living Wage Calculator, the C2ER Cost of Living Index, U.S. Census and Zillow housing data, and city and county sources. Verify current figures before relying on them.
Divide your monthly rent by the number of days in the move-in month, then multiply by the days you occupy the unit. For example, $1,000 rent divided by 30 days times 15 days occupied is $500. Use the calculator above for your dates.
Average rent in Rapid City is about $1,000/month for a 1-bedroom and $1,250 for a 2-bedroom, which is why getting proration right matters when you move mid-month.
In South Dakota the security deposit limit is one month's rent (more by agreement for special conditions). The deposit must be returned within two weeks (45 days with an itemized list) of move-out with an itemized statement of any deductions. South Dakota caps the security deposit at one month's rent (with more allowed by agreement for special conditions) and requires the landlord to return it within two weeks of move-out, or within 45 days with an itemized statement of any deductions. A one-month written notice generally ends a month-to-month tenancy.
In South Dakota, one month (month-to-month) of written notice generally ends a month-to-month tenancy, though your lease may require more. Notice timing also affects your final prorated rent.
There is no statute mandating a specific proration method in South Dakota, but most landlords prorate as standard practice. Confirm the method in writing in your lease before signing to avoid disputes.