October to April is the right window for visiting Giza. Temperatures are manageable — typically 15–25°C — and the hazy sky that makes for poor photographs in summer gives way to cleaner light. December and January can be cool enough in the evenings to need a jacket; the plateau is exposed and the wind off the desert has teeth.
Avoid July and August entirely if you can. Temperatures regularly exceed 40°C and humidity near the Nile pushes the misery further. The plateau has almost no shade, and heat exhaustion among tourists is common. If summer is unavoidable, restrict your outdoor time to the first two hours after the gates open at 8 am and return in the late afternoon around 4 pm.
Ramadan creates a different atmosphere: the city is subdued during daylight hours, some facilities close or reduce hours, but the evenings come alive with Iftar meals and a festive energy that is genuinely interesting to observe. Most tourist sites remain open. The Islamic holiday calendar shifts roughly 11 days earlier each year, so Ramadan's impact varies by season depending on the year.
The Spring Equinox (around 20–21 March) is when the sun sets precisely between the Great Pyramid and Khafre's pyramid when viewed from the Sphinx — a popular date with those interested in astronomical alignments, though the site is busier than usual around this time.