The old way of checking the weather and environmental conditions in your home or yard is to go out there with a thermometer, hygrometer, or light meter, and take readings manually (or maybe just stick your finger in the soil).
The new way is to deploy tiny sensors directly at the site you want to monitor, and then get the data sent right to your iPhone for tracking and analysis.
While nothing can really replace the presence of a real live human for assessing the condition of elements in the environment, having remote sensors that can accurately measure and record specific data about them can be a boon for those who are pressed for time, those who wish for more precise data, those who like to be able to analyze the data for better decision-making, and for those who want to keep their finger constantly on the pulse of things.
Motes are small "stick-able" weatherproof sensors that can be placed just about anywhere you'd like, to keep track of environmental conditions and send you alerts when something needs your attention, such as when your plants need watering, or your aquarium is too hot, or a frost is imminent.
The sensors come in a couple of different flavors, including the Climote (for precision temperature, humidity and light level data), the Growmote (for assessing watering and light needs, and frost danger sensing), and the Thermote (contactless temperature measurement).
The Motes log all of their data every 15 minutes, and send it to an iPhone, iPad, or Raspberry Pi using Bluetooth SMART technology when in range, which is then viewable within the accompanying app. The data can also be synced to the cloud from your mobile device, allowing for trends to be graphed, exported or analyzed from any browser.
Motes measure about 30mm x 30mm x 10mm (Growmote is longer due to the soil probe), and are water- and weather-resistant and designed for use both inside and out. Power comes from common CR2032 batteries, which last about a year before they need replacing, and the effective range for wireless transmission to smartphones is about 30-50 meters (line of sight).