Oregon Scientific RMR382A-BK Wireless Indoor/Outdoor Thermometer for $10.27. Here is a screenshot for your reference. Shipping is free on orders over $25. If needed, use this Filler Tool to pad the order to qualify for free shipping. It features a stand-alone base unit, LCD display, outdoor sensor that transmits data up to 100 feet away, self-setting atomic clock, and more. Most places have it for about $18.