Horary astrology: good weather for my barbecue party?

My husband loves 4th of July fireworks, and this year we’ve invited his family to come barbecue with us and then go downtown to watch the fireworks. My horary question this afternoon: what sort of weather will we have for the party?

(Chart data: 17 June 2008, 5:12pm EDT, Boston, MA. Click to enlarge the chart.)

I am asking specifically about the weather for a party, so I’ll look at what’s happening to the lord of the 5th house, the house of fun and entertainment. If I had a more general question about, say, the weather all summer long, I’d look at the 1st house, describing general conditions where I am.

Aries is on the 5th house cusp. The ruler of Aries is Mars, so Mars is the significator of the party. (Hot, dry, cardinal Aries is, by the way, an appropriate description of a barbecue (cooking) party with fireworks afterwards.) But note that the 5th house cusp describes the party, not the weather at the party.

How will the weather be? Start by looking at the sign that Mars, the party, is in. In this chart, Mars is at 21 Leo 53. Leo is a fire sign: hot and dry. So the day will be hot and dry. Perfectly reasonable for a July day in New England.

To qualify this description a little, we can look at the dispositor of the lord of the 5th house – that is, the planet ruling Leo, where Mars currently is – that is, the Sun. Sun in this chart is at 27 Gemini 02. Gemini is an air sign: hot and moist. So Sun in Gemini increases the heat and adds a little humidity. I note that Sun is also conjunct Venus, the lesser benefic, also in Gemini; so I would say that Venus lends a temperate and pleasant note to the day. Sun/Venus are also widely sextile Mars, another indication that the humidity is pleasant and not unbearable.

So the judgment is clear: a hot summer day, but not an uncomfortable one, and not too dry. If you wanted to keep tweaking your judgment, you could factor in the trine from the Moon in hot, dry Sagittarius; you wouldn’t consider the quincunx from Jupiter, since the quincunx is not a Ptolemaic aspect. Finally, I notice that Mars is on the South Node, which could mean something goes awry at the barbecue… but hey, at least it’ll be a beautiful day.