FiveThirtyEight: “Election junkies need not wait until November 2018 to get their next fix. They don’t even need to wait for the gubernatorial elections in New Jersey and Virginia later this year. Five special elections for the House of Representatives are expected to take place over the next few months: California 34, Georgia 6, Kansas 4, Montana At-large and South Carolina 5.”
“These elections are ‘special’ in the sense that they occur outside the normal two-year November House election cycle — to fill a vacant seat. But other than that, there’s nothing all that special about special elections, making them a decent thermometer reading on the country’s political mood and how voters are responding to President Trump.”
Daily Kos has compiled a spreadsheet of all the important elections in 2017.