How do you feel about setting your request values right there inline?
STATIC<button hx-get="/my/weather/data" hx-trigger="click" hx-vals='{"location": "01245"}'> Click for weather in one static location</button>
DYNAMIC<button hx-get="/my/weather/data" hx-trigger="click" hx-vals='js:{location: document.getElementById("zipcode").value}'> Click for weather in one static location</button>
OR<button hx-get="/my/weather/data" hx-trigger="click" hx-vals='js:{location: someJavascriptCalculationFunction()}'> Click for weather in one static location</button>