Simplest answer first: Nope. Our neighborhood isn't safe to even be out playing on foot, much less ride bikes. The speed limit is 35, but most people do 40-50. And drivers are extra oblivious in our area... because Seattle in general, and our area in particular, doesn't have "neighborhoods". Residential streets have speed limits of 30-35, and the main way to get anywhere in the city is via residential areas. There aren't major roads that link to neighborhoods... but rather one drives through the neighborhoods themselves, clipping along at a min of 30mph the houses a blur on either side. There are a FEW "neighborhoods" that don't connect anywhere / dead end on the lake, but they tend to be uber pricey (million and multimillion dollar houses). Certain streets are worse than others. And most areas don't have sidewalks. The ones that do are pretty sketchy (as in, in bad repair, and will start and stop pretty randomly). Our area is also really high on foot traffic (we're near the university)... so we have maybe ###-###-#### people pass by on foot daily (the higher numbers on game days). Most areas just have the car traffic. Why drivers are extra oblivious is that they get USED to zooming by kids and pets going mach1, so they don't even bother to look for them, much less slow down for them.
The weather is icky here about 10mo a year (50 degrees and drizzling is our standard... but it's been gorgeous all week... we've actually had 4 days of sunshine, and even some blue skies, which is rare). In fact... there's something nicknamed "Seattle Guilt" amongst parents 'round these parts... it's linked to NOT being outside on any day that is actually sunny.
As far as being inside v outside: Until last year we did lots of indoor activities during those 10 months. Gymnastics nearly every day, McDonald's indoor playground, bounce places drop in times, indoor "beach" volleyball - one of the air hangers has both a bounce place and a sand pit for volleyball, the indoor play structure at the zoo & indoor exhibits, swimming - we have lots of indoor pools - only 3 in the city are outdoors, indoor climbing gyms, indoor soccer, indoor basketball, indoor skate parks, and that's not including playing inside the house -including literally climbing the walls, building forts, handstands, skating inside... you name it.
The only outdoor activities we could count on were swimming in July /Aug, and soccer in Aug/Sept (and by the end of soccer everyone is glad of it because we're all miserable and wet). Everything else was hit or miss. Because even if it's not raining, most of the year things are still very wet/muddy.
After investing in a lot of gear we go outside in icky weather (damp/muddy) for things like hiking... but we don't go to playgrounds, because no one goes to playgrounds in the rain. Ditto playdates are inside the vast majority of the time, because of weather issues. Starting last year we started snowboarding in the winter. So we're outside now an average of 10 hours a day 3-5 days a week Nov-Apr... but Sept/Oct/Nov & May / most of June we're stuck doing "rainy day" activities.