This sensor is great for all sorts of weather/environmental sensing and can even be used in both I2C and SPI. This precision sensor from Bosch is the best low-cost sensing solution for measuring humidity with +-3% accuracy, barometric pressure with +-1 hPa absolute accuraccy, and temperature with +-1.0C accuracy. Because pressure changes with altitude, and the pressure measurements are so good, you can also use it as an altimeter with +-1 meter or better accuracy.
The BME280 is the next-generation of sensors from Bosch, and is the upgrade to the BMP085/BMP180/BMP183 – with a low altitude noise of 0.25m and the same fast conversion time. It has the same specifications, but can use either I2C or SPI. For simple easy wiring, go with I2C. If you want to connect a bunch of sensors without worrying about I2C address collisions, go with SPI. The surface-mount sensor is soldered onto a PCB and comes with a 3.3V regulator and level shifting so you can use it with a 3V or 5V logic microcontroller without worry.
Key Features:

BME280 sensor, an environmental sensor with temperature, barometric pressure, and humidity
Used in both I2C and SPI
Measuring humidity with +-3% accuracy, barometric pressure with +-1 hPa absolute accuracy, and temperature with +-1.0C accuracy
Can be used with a 3V or 5V logic microcontroller
Product Dimensions: 25.2mm x 18.0mm x 4.6mm
Product Weight: 1.0g / 0.0oz

Relevant Resources:
Datasheets, PCB CAD files, Fritzing object and more available in the product tutorial